Prime Minister Boris Johnson’s televised statement about Russia’s attack on Ukraine and the UK’s response will be broadcast shortly.

Johnson chaired an urgent Cobra emergency committee meeting this morning and is due to speak in the House of Commons at 17:00 GMT.

In an earlier tweet, Johnson described the Russian assault as “a catastrophe for our continent” and said he would held talks with world leaders.

You can watch Johnson’s statement by clicking the play button at the top of this page.

Nato's chief is calling on Russia to immediately cease military action, withdraw its forces from Ukraine and choose diplomacy

Jens Stoltenberg says in a statement that Russia is using force to try to rewrite history and deny Ukraine its free and independent path.

Nato's core task is to protect and defend all allies, he says.

"An attack on one will be regarded as an attack on all," he says.

He says today the North Atlantic Council - the decision-making body of Nato - decided to activate its defence plans to protect and shield other nations.

It means Nato will deploy its response force to where they are needed, he says.

US President Biden has already been clear that American troops will not be sent to Ukraine.

Explosions and gunfire have been heard across Ukraine after Russian forces invaded the country.

A residential building in Chuguev was destroyed after it was shelled.

Footage shows the devastation being inflicted by the Russian military.

We're continuing to hear from people across Ukraine as the situation develops.

Maria Avdeeva, is a research director at the European Expert Association, she is currently in Kharkiv, Ukraine's second largest city.

She says the “situation is very worrying” after hearing “major shelling” earlier this morning, but says she is going to stay in the city. She is worried about where to take cover if airstrikes begin.

Maria also says she is "ready to fight because it is our land and we didn’t threaten Russia”.

Ukraine is a free, democratic country which wants to be part of Europe and what’s going on is “unbelievable”, she adds.

Image source, Reuters

A Russian journalist and Noble Peace Prize winner has said he and his colleagues are "grieving" over the invasion.

Dmitry Muratov, who edits the Novaya Gazeta newspaper, one of Russia's few remaining independent publications says: "As well as grief, we are experiencing shame."

He accuses Putin of "toying with a nuclear button as if it were a keyring of an expensive car" and asks: "What next - a nuclear strike?"

"I don’t see any other interpretation of Vladimir Putin’s words about 'a weapon of retribution'."

Muratov won the Nobel Peace Prize in 2022 in recognition of his fight for freedom of expression in Russia.

Nick Eardley
Political correspondent

We’re expecting to hear from Prime Minister Boris Johnson soon in a statement about the latest situation in Ukraine.

He will update the House of Commons later too – and it’s expected by then significant new sanctions will be agreed.

There has been criticism in the UK parliament that the sanctions earlier this week didn’t go far enough, so some will be watching the detail closely.

Ministers have said the latest measures will be severe.

There will be a lot of work done today to try and act along with Western allies.

The prime minister will speak to other world leaders soon. And Foreign Secretary Liz Truss will spend the afternoon on the phone speaking to other foreign ministers.

Russia's "unjustified and unprovoked" attack on Ukraine is putting countless innocent lives at risk, says Nato's secretary general, as he continues a news conference in Brussels.

Jens Stoltenberg says Russia has launched air and missile attacks, ground forces and special forces from multiple directions targeting Ukraine's military infrastructure and major urban centres.

"This is a deliberate, cold-blooded and long planned invasion," he says.

Russia's leaders will bear full responsibility for their reckless actions and the lives lost, he says.

Image source, Reuters

Black smoke has been seen rising near the Ukrainian defence intelligence headquarters in central Kyiv.

Ukraine says some of its military command centres have been hit by Russian missile strikes this morning after Moscow launched a military operation against its neighbour.

We'll bring you more on this when we have it.

Nato's secretary general Jens Stoltenberg is now giving a televised statement and taking questions.

He says: "We now have war in Europe of a scale and a type that we thought belonged to history."

He says he has just finished a meeting with the North Atlantic Council and a long list of countries have agreed to hold urgent consulations.

"This is a grave moment for the security of Europe," he says.

The reaction from world capitals to events in Ukraine is coming in thick and fast.

We are now hearing the President Macron of France will give a national address later.

Jessica Parker
BBC Brussels correspondent

The EU only signed off its initial package of sanctions yesterday afternoon.

Now, after developments overnight, it’s already getting ready to propose a second.

"Massive" and "severe" are words we often here about the economic sanctions that the bloc is prepared to inflict on Russia.

But the truth is there are different views among member states about how far the EU should go at this stage.

Germany and Italy are named by diplomats as being jumpy about adopting the heaviest measures, while countries like Lithuania and Poland have long been more bullish.

The truth is that efforts to hurt the Kremlin could hurt Europe too, through business interests and energy supplies.

Leaders now needs to weigh up what costs they might be prepared to pay - as the West faces accusations of having already been too hesitant.

Belarus leader Alexander Lukashenko says Belarusian troops are not currently taking part in the Russian invasion - but could do if needed.

Russian convoys have entered Ukraine from Belarus. Moscow has had troops in Belarus for weeks, ostensibly for military exercises.

"I say again: our troops are not there. But if it is necessary, if it is necessary for Belarus and Russia, they will," Lukashenko said in remarks reported by the state news agency Belta.

Belarus is a long-time ally of Russia. Analysts describe the small country as Russia's "client state".

Within the last hour Nato has released a statement condemning "Russia’s horrifying attack on Ukraine" calling it "entirely unjustified and unprovoked."

The defence alliance, which counts the UK, US and many European countries as members, has also condemned Belarus for "enabling" the attack.

"This renewed attack is a grave violation of international law, including the UN Charter," Nato said. "It constitutes an act of aggression against an independent peaceful country."

The statement goes on to say:, external "Russia’s actions pose a serious threat to Euro-Atlantic security, and they will have geo-strategic consequences. Nato will continue to take all necessary measures to ensure the security and defence of all allies."

As the world comes to terms with today's developments, here's a quick guide to the basics.

Ukraine is located on Europe's eastern border with Russia. It is Europe's second-biggest country by land mass and has been invaded by Russia, the largest country in the world.

Ukraine has a population of about 44m and Russia 144m.

Russia's President Vladimir Putin says his goal is the demilitarisation of Ukraine.

Volodymyr Zelensky has vowed to fight for the country's freedom saying: "We're strong. We're ready for anything."

As a former Soviet republic, Ukraine has deep social and cultural ties with Russia, and Russian is widely spoken there.

Russia seized part of Ukraine's territory when its pro-Russian president was deposed in early 2014. Ukraine has since moved towards European institutions, namely the EU and defence alliance Nato, and Putin wants to prevent any further integration.

• Want more? Here's what we know about the invasion

Here's another account about what's happening in Kharkiv, a city's of 1.4m in Ukraine's north-east. Victoria Vota told us she woke up at 5am to “bombing sounds”.

“My neighbours were ringing my doorbell telling me it’s time to leave and maybe evacuate from the city.”

But she adds the government has been telling us to stay at home if possible, and says “we’re not sure if it’s safe to evacuate”.

She says the army “is doing its best”.

This image shows the impact on aviation in Europe as airlines avoid Ukraine airspace as the crisis in the country intensifies.

Ukraine closed its airspace to civilian flights in the early hours after Russia began its attack.

Image source, Flightradar

UK Transport Secretary Grant Shapps has instructed the Civil Aviation Authority to ensure airlines avoid Ukraine airspace "following the horrific events overnight".

Foreign Secretary Liz Truss says she has summoned Russia's ambassador to the UK to "explain Russia’s illegal, unprovoked invasion of Ukraine".

"We will be imposing severe sanctions and rallying countries in support of Ukraine," Truss tweeted, external.

Prime Minister Boris Johnson is expected to announce tougher sanctions against Russia later today and give a televised statement later.

Image source, Tetiana Kashtanova

In the wake of Russia's attack, we're hearing from residents of Kyiv who are coming to terms with the news.

Tetiana Kashtanova, from Kyiv says: “We woke up at 5am because we heard some explosions. That’s how our day started.

"Many people are trying to leave right now so we have a giant traffic jam.”

Tetiana says she doesn’t know what will happen and it feels dangerous to leave but “if there is an option for us to leave to the West we will take it".

Earlier she had taken cover in an underground car park, but is now back in her flat.

“We’re talking to our friends trying to calm everyone down" she says, adding "we believe in our army".

If you're just joining us, welcome. It's a fast-moving situation in Ukraine and we're working to keep you up to date. Here's the latest we know about the invasion.

• In a televised address early on Friday Russia's President Vladimir Putin ordered a "military operation" in Ukraine's eastern Donbas region but what's been launched goes far further and amounts to a full-scale attack on the country
• Russian military vehicles were said to have breached the border in a number of places, in the north, south and east, including from Belarus. At least seven people are known to have been killed in Russian attacks, police say. Another 19 are missing

• Multiple explosions were heard in the city of Odesa within the past hour
• More than 40 Ukrainian troops have been killed in Russian shelling, Ukrainian president's office says, but this has not been independently confirmed
• CCTV images issued by the State Border Guard Service of Ukraine reportedly show Russian military vehicles moving across the border from Crimea

• BBC correspondents have heard explosions in the capital Kyiv, as well as Kramatorsk in the Donetsk region of eastern Ukraine
• The Ukrainian armed forces say they have shot down five Russian planes and a helicopter; Russia has dismissed these claims
• Emergency sirens have sounded in Kyiv and huge traffic jams have built up as residents flee the city

Missile strikes and explosions have been reported near major cities in Ukraine as Russian forces launch a major military assault.

There are lots of reports right now on where attacks are taking place. You might have seen some videos on social media - we are looking at what's out there and verifying they are real before sharing them.

Image source, Getty Images