Image source, Reuters

President Joe Biden will shortly announce the release of a record amount of oil from US strategic stockpiles, says the White House.

It says an unprecedented one million barrels a day will be released to the market from US reserves for the next six months.

It hopes the move will dampen soaring fuel prices in the wake of Russia's invasion of Ukraine.

Oil prices began to fall earlier today after reports emerged that the US was considering tapping its crude reserves.

Russia’s former foreign minister has been speaking on the BBC’s Global Questions programme.

Asked if Vladimir Putin's plans to weaken Nato have backfired by invading Ukraine, Andrei Kozyrev says “he miscalculated everything.”

He goes on to criticise Putin’s track record in office, saying Russia is “declining” because it’s too dependent on exports of raw materials.

Kozyrev served in the government of Boris Yeltsin in the 1990s.

You can watch the broadcast now on BBC World News, the BBC News Channel and by clicking the play button at the top of this page.

Here's a reminder of some of the international reaction to President Putin's threat to cut gas supplies to "unfriendly" countries if they don't start paying for gas imports in Russian roubles.

Western companies and governments have rejected Russia's demands as a breach of existing contracts, which are set in euros or US dollars.

Germany is Russia's largest customer in the EU. The country's economy minister, Robert Habeck, said: "It is important for us not to give a signal that we will be blackmailed by Putin."

And German finance minister Christian Lindner echoed his words: "It is clear for us there can be no political blackmail."

He added: "We are convinced that contracts are contracts. The contracts are based on euro and so we will continue to pay for energy imports in euro."

France also insists "contracts are contracts".

In the UK, Prime Minister Boris Johnson says paying in roubles is "not something we will be looking into".

Dutch energy company Eneco states it has a long-term contract with Wingas, a German subsidiary of Russia's Gazprom, for delivery until 2030.

"Eneco expects its current contract with Wingas in euros to be honoured," it added.

Find out how reliant the world is on Russia for oil and gas here.

Could Ukraine 'win' the war? And other questionspublished at 17:26 British Summer Time 31 March 2022

17:26 BST 31 March 2022

Thanks for all the questions you submitted to Jenny Hill in Moscow and Orla Guerin in Kyiv. You can now find all the answers here. We'll provide more chances in the future for you to send in your questions to our correspondents around the world.

In the meantime we'll continue to bring you the latest developments, analysis and reaction to the war in Ukraine.

Image source, Reuters

The United States has imposed fresh sanctions on Russia, this time targeting its technology sector, external.

The US Treasury said it was imposing sanctions on 21 entities and 13 individuals, including Mikron, Russia's largest chipmaker ands its largest manufacturer and exporter of microelectronics.

The move was intended to target "sanctions evasion networks" and "key Russian technology companies that are enabling Putin’s illegal war against Ukraine".

Among those sanctioned were also "Russian government malicious cyber actors," the US Treasury said.

"We will continue to target Putin’s war machine with sanctions from every angle, until this senseless war of choice is over," Treasury Secretary Janet Yellen said in the statement.

Moscow faces a wide range of international sanctions on sectors ranging from military goods to luxury items, air travel and banking.

Ukraine's state nuclear company Energoatom says many of the Russian troops holding the Chernobyl nuclear power plant have left, Reuters news agency has reported.

Energoatom said the departing Russian forces are heading for the Belarusian border, leaving just a few troops behind on the territory of defunct plant - the site of the world's worst nuclear disaster in 1986.

"The occupiers, who seized the Chernobyl nuclear power plant and other facilities in the exclusion zone, have set off in two columns towards the Ukrainian border," Energoatom said in a statement.

It added that Russian troops had also withdrawn from the nearby town of Slavutych, where Ukrainian workers at Chernobyl live.

Russian troops seized control of the Chernobyl plant on the first day of Vladimir Putin's invasion of Ukraine.

Ukraine had voiced safety fears about the plant and the difficult conditions workers trapped there were having to endure.

Russia denied that its forces put nuclear facilities inside Ukraine at risk.

Kasia Madera and Rebecca Hartman
Lublin, Poland

Tatiana and her children fled Ukraine in the boot of a car two days after Russia invaded.

This morning, her daughter played with her new friends in a breakfast club as Tatiana prepared for her first day working in a new school, in a new country - Poland.

Back home in Ukraine, Tatiana is a teacher. Here, the Polish city of Lublin is the first in the country to bring in a cash-for-work scheme for refugees, which is paying Tatiana to teach.

The scheme involves 47 refugee teachers being placed in 39 schools across the city to support the 1,500 new pupils who have started school over the past month.

Lublin has been widely praised for how NGOs, local government and volunteers have worked together to support refugees, by integrating them into schools, workplaces and life in the city.

The city of 350,000 people is currently hosting around 40,000 Ukrainian refugees. Almost 2.4 million people have fled Ukraine to Poland since the war began.

Schemes here in Lublin are now being rolled out across the country to help those in need.

Germany and France have already both come out to say they reject Russia's demand for gas payments to made in roubles.

Asked whether the UK would accept Russia's demand, a spokesman for Prime Minister Boris Johnson said it was not something it would be looking into.

He added that the UK was monitoring the implications for the European market.

Coming up at 17:05 BST (16:05 GMT) you can watch Global Questions: Ukraine Crisis: What Next for Europe? live on BBC World News, the BBC News Channel and streamed here, at the top of this page.

Hosted by Zeinab Badawi live from Warsaw University of Technology, a panel will discuss the prospects for a peaceful solution and how Europe might look after the war in Ukraine.

They will also examine what more the European Union and the Nato military alliance can do to help protect and further integrate the so-called "frontier states".

Also on the agenda: how will Poland cope with the sudden influx of more than two million refugees?

Image source, Getty Images

Here are some of today's main developments:

On the international stage:

• Russian President Vladimir Putin has announced that from tomorrow foreign buyers of Russian gas will have to pay in roubles by opening a Russian bank account or have their contracts cancelled
• In response, Germany - Russia's largest EU customer - said it would not be blackmailed, while France said it was planning to cut Russian gas deliveries
• The Kremlin has responded to US claims that Putin has been "misled by the Russian military" by saying that Washington does not understand the Russian president
• It comes after the head of GCHQ, the UK's intelligence, security and cyber agency, said Putin was being misled by his advisers and had made a miscalculation in his invasion of Ukraine
• The UK government has announced further sanctions against Russia, most of which target media figures

On the ground:

• A convoy of buses is on its way to Mariupol in a bid to evacuate civilians from the besieged port city after Russia agreed to a ceasefire to allow civilians to leave
• The International Committee of the Red Cross says it is ready to lead the evacuation operation if both sides agree to terms, after previous efforts collapsed
• Shelling appears to have continued around Kyiv and Chernihiv despite Russia having said it would scale down its operations there
• Ukraine's state nuclear company has said that many of the Russian troops holding the Chernobyl nuclear plant have left, according to Reuters news agency

Who will pay to rebuild Ukraine's infrastructure?published at 15:48 British Summer Time 31 March 2022

15:48 BST 31 March 2022

Orla Guerin
BBC News, Kyiv

And now for our final question. Steve Sandercott from Rugby asks who is going to pay to rebuild the damage inflicted on infrastructure in Ukraine - never mind the human cost?

The greatest cost is the human one and that is increasing by the day.

The verified civilian death toll, according to the United Nations, is about 1,200 people, but the real number will be far higher.

Add to this the fact that four million Ukrainians have had to flee and become refugees in other countries.

There is also extensive physical destruction, in cities and towns across this vast country.

Nowhere has suffered more than Mariupol in the south, where we spent 10 days in the countdown to the invasion.

At that point it was a bustling port city, with trendy cafes, busy restaurants, and families strolling in the parks.

Satellite imagery of Mariupol now shows mostly scorched earth, with 90% of residential buildings damaged or destroyed.

Image source, Reuters

As many as 5,000 people are known to have been killed in this city alone, according to Ukrainian officials.

They say the actual death toll could be twice that.

Ukraine’s President in Volodymyr Zelensky has promised to restore “every house, every street and every city”.

He says Russia will have to “learn the word ‘reparations’” and pay the full cost.

Ukraine will certainly want reparations to be a key part of any deal done to end the war, but how much Russia pays will depend on who has the upper hand when that deal is done.

Theoretically, Russian assets abroad, frozen by G7 countries, could be used to help foot the bill.

Does recruiting from the Middle East show a lack of trust in Russian forces?published at 15:39 British Summer Time 31 March 2022

15:39 BST 31 March 2022

From David Carter

Jenny Hill
BBC News, Moscow

The Kremlin would never admit to it but there is evidence that at least some of the Russian troops are inexperienced and unprepared for their mission.

The Ministry of Defence was recently forced to admit that - contrary to Vladimir Putin’s claims - conscripts had been sent to fight in Ukraine.

Moscow claims to have 16,000 Middle Eastern "volunteers", many of whom fought against ISIS in the last decade, ready to join Russian troops.

They may have more experience than some of their Russian counterparts and some experts say they’d likely be more skilled in the kind of urban combat necessary to take cities and towns.

Some argue too that they'd be less reluctant to attack or kill Ukrainian civilians (many Russians have close ties to Ukraine and consider the people there to be "brethren") and that they have a reputation for brutality which could have a psychological effect on Ukrainian troops.

The Kremlin presumably knows all this, which is why it was so keen to publicise its access to Middle Eastern fighters - even though it has not yet officially confirmed that it will actually send them in.

How big an issue will unexploded ordnance be for Ukraine after the war?published at 15:37 British Summer Time 31 March 2022

15:37 BST 31 March 2022

Orla Guerin
BBC News, Kyiv

Robbie asks to what extent will unexploded ordnance remain an issue for Ukraine after the war? Is there potential for large areas of land to be deemed inaccessible as a result?

Sadly yes, as so often in conflict, the danger to human life will remain long after the guns eventually fall silent.

The danger comes not only from unexploded ordnance but also from landmines.

They can kill for years to come, unless and until de-mining organisations can clear frontline areas.

I have seen these organisations at work after other wars. Their work is painstaking, and time-consuming.

Before the invasion began there was already a war raging in the east of Ukraine between Russian-backed separatists and the government of Ukraine.

It began in 2014 and has dragged on ever since.

While reporting from front lines there in late January and February we had to carefully skirt many minefields. At that time the snow was melting turning the soil to mud.

In these conditions mines can easily shift from their original locations (which may have been marked on maps or fenced off).

Currently in the commuter town of Irpin, north of Kyiv, the Ukrainian army says there is a high risk to life because of mines in the streets.

Image source, Getty Images

France and Germany are preparing for a cut in Russian gas deliveries, France's economy minister has said.

He was responding to Russian President Vladimir Putin's warning that Moscow would turn off the taps for those who refuse to pay in roubles.

"There could be a situation tomorrow in which... there is no longer any Russian gas.

"It's up to us to prepare for these scenarios and we are preparing," said Bruno Le Maire following talks in Berlin with his German counterpart Robert Habeck.

Is it possible to get Russian views from the front lines?published at 15:17 British Summer Time 31 March 2022

15:17 BST 31 March 2022

Robert, 59, Bishop’s Stortford

Jenny Hill
BBC News, Moscow

Robert from Bishop's Stortford asks we are seeing the point of view of front line Ukrainian soldiers, but is it possible to get the perspective from the Russian side? Are you prevented by the Russians from reporting on and talking to Russian troops on the ground in Ukraine?

I can’t answer for my colleagues currently in Ukraine, but the Kremlin tightly controls the flow of information back to Russia.

The Ministry of Defence issues frequent updates which consistently emphasise the success of the "special military operation".

Russian soldiers are banned from using smartphones, and Moscow has made it a criminal offence to publish information which would discredit the Russian military or to spread what the Kremlin would deem to be fake news about it.

An independent organisation exists which aims to help families of servicemen to get information about them.

However, they’ve recently told us that they’re under considerable pressure from the authorities to stop their activities.

Image source, Getty Images

Is there a possibility news reported by Ukraine is not wholly accurate?published at 15:16 British Summer Time 31 March 2022

15:16 BST 31 March 2022

Orla Guerin
BBC News, Kyiv

Sarah from Oxford asks: Putin has placed massive restrictions on the media in Russia, but is there a possibility that news reported by Ukraine - for example, the numbers of deaths of troops and civilians, - is not wholly accurate?

Both sides are fighting an information war, as well as the war on the battlefields.

In any conflict, information from any of the warring parties - about civilian deaths, territory captured, or enemy soldiers killed – has to be taken with caution.

This is especially true now in relation to Russia - which is trying to ensure that its people receive only the Kremlin’s version of events.

It still refuses to admit that it invaded Ukraine and refers only to its “special military operation”.

We prioritise first-hand reporting, which is why the BBC has teams in so many parts of Ukraine - gathering testimony from people on the ground, including civilians, medical staff, local officials and the Ukrainian military.

Ukraine is acknowledging that it has suffered losses, and BBC teams in different cities have been able to report on the funerals of Ukrainian soldiers killed in battle.

We can’t know yet if the full extent of the losses is being made public.

Image source, EPA

Jenny Hill
BBC News, Moscow

Vladimir Putin said that from tomorrow foreign buyers of Russian gas must pay in roubles.

In practice Western governments will have to open an account at Gazprom bank and transfer euros or dollars into it.

The bank will use the currency to buy roubles on the stock exchange which will then be used to make the payment.

Putin was on belligerent form telling Russians that the West has been waging an economic war against his country for years in order to undermine its development.

But he said Western sanctions were the price Russia must pay for freedom and independence.

In response to Russia's move to make foreign buyers pay into rouble accounts for Russian gas, Germany has said it will not be blackmailed by Putin.

Robert Habeck, the economy minister, says allies with whom he's spoken believed existing gas contracts must be respected, Reuters news agency is reporting.

He adds that he's yet to see any new gas bill from Russia - and insists they are prepared for anything Putin might decide on gas.

Russian gas accounts for about 40% of the EU's natural gas imports, external, with Germany the largest customer by far.

How would Crimea and Donbas be dealt with in peace deal?published at 14:53 British Summer Time 31 March 2022

14:53 BST 31 March 2022

Jenny Hill
BBC News, Moscow

Back to some of your questions now.

Ryan McGauley asks if a peace deal were to happen, how would Ukraine and Russia deal with Crimea, the regions taken by Russia in the Donbas this past month, and the areas that have been controlled by Russian-backed rebels for the past few years?

We know that Vladimir Putin wants the world to recognise Crimea, which Russia annexed in 2014, as Russian.

Ukraine has suggested that Crimea’s status be negotiated as part of a peace deal though it’s hard to see Vladimir Putin agreeing to that.

He also wants the international community to recognise (as he has) the self-proclaimed peoples' republics of Donetsk and Luhansk as independent (although this would basically mean "Russian-controlled").

Given that the Kremlin’s current plan is to intensify its efforts in eastern Ukraine in order to "liberate" the whole Donbas region, we can assume that Mr Putin intends to try to take - and hold on to - the region.

Image source, .

Here's some more from Vladimir Putin who says that in order to buy Russian natural gas, foreign buyers must deal in the Russian currency.

From 1 April, they will have to open special Russian bank accounts to transfer foreign funds and the bank will then use them to purchase roubles.

"If such payments are not made, we will consider this a default on the part of buyers, with all the ensuing consequences," he says.

"Nobody sells us anything for free, and we are not going to do charity either - that is, existing contracts will be stopped."

Major EU economies such as Germany and Italy rely on Russian gas for significant energy needs.

Ukraine's government has said this reliance has stopped certain EU nations from providing the level of support desired from the West to fight Russia's invasion.

Image source, .