Image source, Reuters

The Scotttish government's offer to act as a super sponsor for Ukrainians seeking refuge in the UK is now open.

This means Scotland could welcome 3,000 Ukrainians without delay, according to First Minister Nicola Sturgeon.

The super sponsor scheme will provide people fleeing the war in Ukraine with temporary accommodation in Scotland, while longer-term lodging is found.

With the Scottish government acting as a super sponsor, those fleeing the Russian invasion could come to Scotland "immediately" - rather than waiting to be matched to an individual host.

"To those Ukrainians arriving in our country, I can say we will treat you with compassion, dignity and respect," Sturgeon said today, adding "and I extend a warm welcome to Scotland, our home - and, for as long as you need it, yours too."

Gordon Corera
Security correspondent, BBC News

On a map it was easy to think there had been a stalemate in the last two weeks but the reality was there had been "some pretty ferocious fighting" in contested areas, a western official has said.

The failure of Russia's original plan had led to a "change their approach. It's forced them to have to reorganize and regroup," they said.

The Russians had made most progress in the south, they said, but overall it remained slow compared to their plan, although the risk of encirclement of the main Ukrainian force, part of Russia’s original plan, remained.

The officials say Russia is trying to make up for its losses, but will have a challenge in forming the "slightly odd mix of different groups" they are recruiting into an effective fighting force.

An official says Russian forces hold "an enormous amount of artillery ammunition" which could allow them to mount a "bombardment" that lasts for weeks - or longer.

They say the loss of senior Russian commanders is "very difficult to obscure from the population" and poses challenges when it comes to "control of the media".

"There is going to be a challenge, I think, over how they retain control of the narrative when they've got losses, both at the scale that they have, but also at the profile that some of these senior officers will have," one official says.

The officials say President Vladimir Putin's inner circle remains "stable and united" - "not perhaps necessarily on the basis of satisfaction with what's happening, but because they will recognise that they are they are chained together as a group".

They add that the West is keeping "a very close watch" on potential escalation, which could involve cyber, chemical or biological weapons as well as nuclear.

Many have reportedly been killed in a Russian missile attack on Ukrainian army barracks in the strategic southern city of Mykolaiv.

A Ukrainian MP in Odesa, Oleksiy Honcharenko, returned from Mykolaiv in the last 24 hours and has been speaking to the BBC.

"Unfortunately we had a big attack, missile attack on Mykolaiv. Dozens of people have been killed," he said.

"Dozens are wounded and we're speaking about missiles, ballistic missiles."

Ukrainians are reportedly continuing to defend the city, with Russian forces grouped outside, to the northeast.

The city of Mykolaiv, which is crucial to Russia's plans to take Ukraine's third city, Odesa, has been holding back a Russian offensive along the Black Sea coast.

"Mykolaiv is fighting fiercely on the ground and holding the ground and Russia just couldn't take it so they started terror against local people, civilians," Honcharenko added.

Image source, White House

We have more information now on the video call between Joe Biden and Xi Jinping earlier today.

Details about the two-hour call are still sparse, but the White House says Biden "described the implications and consequences if China provides material support to Russia as it conducts brutal attacks against Ukrainian cities and civilians".

Meanwhile, the Chinese Ministry of Foreign Affairs says Xi made it clear during the meeting that "as permanent members of the UN Security Council and the world’s two leading economies, we must not only guide the China-US relations forward along the right track, but also shoulder our share of international responsibilities and work for world peace and tranquility".

As we've been reporting, Russian cruise missiles this morning hit an aircraft repair plant in Lviv, western Ukraine, according to the Ukrainian air force.

Lviv's mayor said Russian missiles had struck the area near the airport, hitting an aircraft repair plant building but not the airport itself. The plant had stopped working and no-one was hurt, he said.

As the below graphic shows, the Ukrainian air force has been seriously hit by the Russian invasion.

While military losses are difficult to quantify, the Pentagon has said a little over half of Ukraine's fighter aircraft is still operational in comparison to its pre-war total.

If you are just joining us, or want a recap, here's a summary of some of the main events:

• Fighting has reached the centre of the southern port city of Mariupol, both sides have confirmed, where many civilians are still trapped and more than 80% of residential buildings are either damaged or destroyed
• President Zelensky said just 130 people have been rescued from the basement of the city's theatre, which was bombed on Wednesday. Some 1,300 are said to still be inside
• There are reports of mass casualties following a missile attack on a Ukrainian army barracks in the southern city of Mykolaiv - it comes as the UN says that at least 816 civilians have been killed so far
• Russian-Ukrainian negotiations continue. Moscow claims they are "halfway there" but Ukraine say their position remains "unchanged"
• President Putin has addressed tens of thousands of cheering Russians, at a rally in Moscow celebrating eight years since the annexation of Crimea
• President Zelensky says he's spoken to EU Commission chief Ursula von der Leyen, and he expects quick progress on Ukraine's application for fast-track EU membership

This footage shows the extent of destruction in the southern port city Mariupol, as Mayor Vadym Boichenko tells the BBC fighting has reached the city centre.

Former Prime Minister David Cameron is driving a lorry to Poland with a delivery of donations to the British Red Cross.

The donations - including clothes, nappies and first aid - come from a community food project, the Chippy Larder, with which he has volunteered for the past two years.

Mr Cameron praised "the generosity of the community in west Oxfordshire - and of the British people more generally" as being "typically phenomenal, stepping up to help our neighbours in their hour of need".

Speaking earlier, Ukraine's ambassador in the UK today welcomed all the support being offered by the British people, but said "money would be better placed" rather than bulky items.

"The message is simple: if you can, give a couple of pounds rather than bring stuff in a bag," he said.

Ukraine is "humbled" by the more than 150,000 people in the UK who have offered a home to refugees fleeing the Russian invasion.

Vadym Prystaiko - Ukraine's ambassador in the UK - acknowledged it had been a "bumpy ride" overcoming British bureaucracy to bring Ukrainian refugees to the UK.

But he told the PA news agency he was "very grateful that the UK Government and citizens are opening up their hearts and sometimes homes" as part of the Homes for Ukraine scheme, which launched on Friday.

"I'm humbled by the sheer number of people who are opening up - sometimes just saying I have a spare room, it's not even a spare house, or flat, it's just a spare room. This is something that's very unusual."

The ambassador estimates up to 200,000 of his country's citizens may seek temporary refuge in the UK.

Earlier today, President Zelensky tweeted that he was in regular conversation with Boris Johnson and "grateful for the strong support" from the UK.

Russia has accused Canada of "kindergarten-level" diplomacy in a Twitter row over an annotated letter.

The diplomatic spat is over a letter signed by Russian diplomat Vassily Nebenzia, which was sent to all UN members on Wednesday.

The letter seeks support for a draft Russian resolution about aid in Ukraine.

Canada's official UN mission Twitter account posted pictures of the letter, external with "suggested edits" in red type, which led to retweets from other UN missions.

Where Nebenzia says he is "reaching out with regards to an urgent matter related to the dire humanitarian situation in and around Ukraine", Canada's annotation adds: "which we have caused as a result of our illegal war of aggression".

A Russian diplomat has called it "Russophobic libel".

Russian forces "remain largely stalled across" Ukraine, but have around 90% of their "assembled combat power still available to them", a senior US defence official says.

In a statement, the official says Russian forces have not made "significant advances" toward Kyiv in the north or north west, and there is "no movement of Russian forces" to the east of the capital.

They point to "heavy resistance from the Ukrainians" but say the besieged southern city Mariupol "remains isolated".

"We continue to see heavy bombardment there. Ukrainians are defending the city," they add.

More than 1,080 Russian missiles have been fired since the beginning of the war, the US official says.

The statement says reports of missile strikes in the vicinity of Lviv International Airport "appear to be accurate" - but the extent of any damage is unknown.

More now on Russian-Ukrainian negotiations.

Moscow's negotiator Vladimir Medinsky said earlier that the two sides are "halfway there" in agreeing on the issue of Ukraine's demilitarisation, and their views are most aligned on Ukraine's neutrality and giving up on joining Nato. (See our post at 4:32)

But Kyiv's negotiator Mykhailo Podolyak says that Russia is attempting to "provoke tension in the media" and that Ukraine's position remains unchanged.

Fergal Keane
BBC News, Lviv

Mariia Grinchenkova arrived in Lviv this morning after being evacuated from Mariupol, which has been under constant bombardment.

Like some of the other refugees arriving in Lviv today, the 86-year-old had been sheltering in Mariupol's theatre.

She left with her family the day before the building was hit in an airstrike.

But she was injured beforehand, when she collapsed inside the basement shelter.

Her daughter, Ludmila, explains that her mother had been sitting for nine days and when she finally stood up “she collapsed because she was dizzy".

Greece is "ready to rebuild" a maternity hospital that was destroyed by bombing in the besieged southern port city Mariupol, the prime minister says.

In a tweet, Kyriakos Mitsotakis calls, external Mariupol "the centre of the Greek minority in Ukraine, a city dear to our hearts and symbol of the barbarity of the war".

His comments come a day after the Italian culture minister, Dario Franceschini, said, external Italy was "ready to rebuild" the city's theatre.

"Theatres of all countries belong to the whole humanity," he tweeted.

Lyse Doucet
Chief International Correspondent, Kyiv

For the past two days, rescue workers have been pulling people from the wreckage of the Mariupol theatre.

The elegant building, a cultural landmark, is now in ruin but its underground bunker is believed to have protected more than a thousand people, mainly women and children, sheltering there.

But it’s painstaking and perilous work in the midst of continued shelling.

Ukraine’s President Volodymr Zelensky has now confirmed that 130 survivors have been recovered, but hundreds more remain trapped. He's accused Russia of deliberating dropping a bomb on the theatre - Russia denies that.

But Russian forces have bombarded and encircled Mariupol for weeks, stopping desperately needed aid from getting in, and stopping people from getting out. And the fighting has now reached the centre of this strategic port city.

Mariupol lies along a stretch of southern territory Russia wants to control to link eastern Ukraine and the Crimean peninsula which have been under its sway since 2014.

The agony of Mariupol has become a symbol of civilian suffering across Ukraine.

Image source, Reuters

Health Secretary Sajid Javid has called President Putin "a war criminal", echoing the words of US President Joe Biden.

At the Conservative Spring Forum, Mr Javid spoke of "the storm clouds of war" in Europe and his anger and sorrow at hearing "reports of mass graves at Mariupol and the murder of pregnant women".

"Let's make no mistake, Vladimir Putin is a war criminal.

"He's a threat to free people everywhere, and he will be held to account," Javid said.

On Thursday, fellow cabinet ministers Liz Truss and James Cleverly appeared reluctant to use the term war criminal when referring to Putin.

The Kremlin has called Biden's use of the phrase "unforgiveable rhetoric".

It appears China and the US need each otherpublished at 16:45 Greenwich Mean Time 18 March 2022

16:45 GMT 18 March 2022

Anthony Zurcher
BBC North America reporter

Joe Biden has said that the world is in the midst of an era-defining clash between democracies and autocracies and that the US would orient its foreign policy according.

In practice, that has proved somewhat challenging.

Instead of confronting China, the nation the US has identified as its chief strategic rival, the US is seeking China's help in condemning and punishing Russia for its invasion of Ukraine. Or, at least, it wants China to promise not to help Russia.

That was the goal of Biden's Friday call to Chinese leader Xi Jinping - a communication that was either jointly agreed to (according to the Americans) or requested by the US (according to Chinese).

Details of the conversation will emerge over time, when the vague language released so far is - or isn't - translated into action.

For the moment, however, it appears both sides need each other.

The US wants Russia to know that it is truly alone if it continues its attacks in Ukraine and that China won’t bail Vladimir Putin out, economically or militarily.

China wants to avoid being caught up in the anti-Russia sanctions imposed by the US and its European allies, the prospect of which has caused its economy to falter of late.

It may turn out the predicted era-defining conflict is less black-and-white than shades of grey.

Moscow and Kyiv are "halfway there" in agreeing on the issue of Ukraine's demilitarisation, and their views are most aligned on Ukraine's neutrality and giving up on joining Nato, Russian negotiator Vladimir Medinsky says.

The Russian Interfax news agency quotes Medinsky as saying negotiating teams have been discussing security guarantees should Ukraine no longer attempt to join the Western military alliance.

President Vladimir Putin yesterday told Turkish President Recep Tayyip Erdogan what Russia's precise demands were for a peace deal with Ukraine.

Chief among them is an acceptance by Ukraine that it should be neutral and should not apply to join Nato. Ukraine's President Volodymyr Zelensky has already conceded this.

There are other demands in this category, which mostly seem to be face-saving elements for the Russian side. Ukraine would have to undergo a disarmament process to ensure it wasn't a threat to Russia. There would have to be protection for the Russian language in Ukraine.

Read more: Putin lays out his demands in Turkish phone call

Hugo Bachega
BBC News, Lviv

Mariupol Mayor Vadym Boichenko tells me fighting has reached the city centre, confirming earlier Russian reports.

"Yes, they were really active today. Tanks and machine gun battles continue," he says. "Everybody is hiding in bunkers"

He says more than 80% of residential buildings are either damaged or destroyed, and 30% of them cannot be restored.

"There’s no city centre left. There isn’t a small piece of land in the city that doesn’t have signs of war," he says.

The operation to rescue people from the basement of a theatre that was bombed continues, he adds, without giving any estimate on casualties.

Will Vernon
BBC News, Moscow

Earlier today, Russian President Vladimir Putin addressed tens of thousands of cheering Russians, crammed into Moscow's Luzhniki Stadium, at a rally celebrating eight years since the annexation of Crimea.

I spoke to dozens of those queueing to enter the venue for the pro-Kremlin rally.

Many told the BBC they worked in the public sector, and that they had been pressured into attending by their employers.

One man who works in the Moscow metro told us that he and other employees had been forced to attend the rally.

Image source, Getty Images

"I'll be here for a while and then I'll leave… I think most people here don't support the war. I don't," he said.

Many people didn't want to be filmed or answer questions.

Students told us they had been given the option of a day off from lectures if they attended "a concert".

Some of the students we spoke to didn't even know that the event was dedicated, in part, to support the war in Ukraine.

There were doubtless some people in attendance who genuinely support President Putin and the "special military operation in Ukraine", as the Kremlin prefers to call it.