Earlier, US President Joe Biden spoke to Ukrainian leader Volodymyr Zelensky over the phone about the Russian invasion.

The two leaders discussed sanctions against Russia, and military assistance to Ukraine, Zelensky said in a tweet, external.

The US president tweeted about the call ahead of his first State of the Union address at the Capitol in Washington. We'll bring you details of that speech later.

The UK is imposing sanctions on Belarus for its role in the Russian invasion of Ukraine, the government announced on Tuesday.

Foreign Secretary Liz Truss said the sanctions were being launched against individuals and organisations because of the role the country is playing in Russia's invasion of Ukraine.

Speaking to reporters from Reuters and CNN earlier, Ukrainian President Zelensky reflected on the image that has emerged of him over the course of the last few days.

Today's crisis is "very serious, it’s not a movie," the actor turned commander-in-chief told CNN, adding: "I’m not iconic, I think Ukraine is iconic.”

Before assuming office, Zelensky had been a comedic actor and was the Ukrainian-dubbed voice for Paddington Bear in a film. He also had a law degree and won office in 2019 on a promise to crack down on corruption.

“Ukraine is the heart of Europe, and now I think Europe sees Ukraine is something special for this world,” he said. “That’s why [the] world can’t lose this something special.”

Image source, Beata Zawrzel/Anadolu Agency via Getty Images

Scotland's First Minister Nicola Sturgeon has called on the UK government to waive all visa requirements for Ukrainians fleeing the Russia invasion of their country.

In a letter to Prime Minister Boris Johnson, she said the current proposals were "still insufficient given the gravity of the situation".

It was announced earlier on Tuesday that more Ukrainian nationals would be allowed to enter the UK to join family members.

Sturgeon urged Johnson to offer "immediate refuge and sanctuary, where necessary" for those who may be displaced.

Her letter also says that Scotland stands ready to offer refuge and sanctuary for those who may be displaced, as it did with the Syrian Resettlement Programme.

A UK government spokesman said: "The United Kingdom with Scotland within it has a strong and proud history of supporting people in need and that will never change."

Image source, Getty Images

Daniel, a father-of-three living in Kharkiv, tells the BBC he's had no choice but to leave the city he loves because he won't put his family in danger.

"I tried my utmost to stay in the city until today," he says, but their home was just 1km (0.6 miles) from the government offices that were attacked on Tuesday morning.

He's now travelling towards Moldova or Poland with his wife and children, aged eight, four and 18 months - while his mother and mother-in-law are staying behind in Kharkiv.

"I love my country, I love my city," Daniel says. "It is a very beautiful city. But now it's been demolished." At the moment he doesn't know when he will return.

His eight-year-old daughter gave a message via her father, saying: "She wants everyone to live in peace and stop the war - because war ruins harmony."

Vitaly Shevchenko
BBC Monitoring

The Russian military has been reluctant to acknowledge losses in Ukraine, but regional authorities say compensation is being offered to the families of killed Russian servicemen.

Ekho Moskvy radio quoted Chechen leader Ramzan Kadyrov, external as saying that their relatives will be paid 2m roubles (under $20,000 at the current exchange rate, £15,000).

The same sum was also mentioned by Krasnodarsk Territory governor Veniamin Kondratyev, who named one Russian soldier killed in Ukraine.

"I understand that nothing can soothe the pain of your loss, but we will not leave anyone alone and will support them as much as we can," he said, external.

Five people have died after Russian forces hit a TV tower in Kyiv on Tuesday, officials say.

The attack took some broadcasts off air, and damaged a nearby memorial to the victims of the Nazi Holocaust.

Footage shows a large blast and smoke billowing from the tower.

Earlier Ukraine's defence minister, Oleksiy Reznikov, warned that Russia was planning to disrupt communications and spread fake information about a Ukrainian capitulation.

Volodymyr Zelensky has spoken to Western media from a secret bunker in Kyiv, saying "Ukraine will fight stronger than anyone else" but that it cannot manage the war against Russia on its own.

The Ukrainian president, who has emerged as a heroic figure in his country's defence for his defiance in the face of Russian aggression, told CNN and Reuters that ceasefire talks could only be serious if fighting stopped first.

"If you do this, and both sides do this, it means they [Russia] are ready for peace," he said. "If they don't ready [sic], it means you're just wasting time."

"We'll see [if they're ready]," he said.

Zelensky, who spoke to US President Joe Biden in the last few hours, said he wanted the US leader to address the situation in Ukraine in his state of the union speech tonight, according to CNN. He reportedly wants to hear Biden explain that Ukraine's resistance is not just about one country, but about democracy and freedom, and that Americans "should care about it".

Image source, None

Footage has emerged of destroyed residential buildings which eyewitnesses say were bombed in the town of Borodyanka, in the Kyiv Oblast region of Ukraine.

The social media videos have been verified by the BBC.

In one of the clips a man can be heard saying civilians are being bombed: "No troops here, just ordinary residents of Borodyanka - grannies, grandads, kids. People are sheltering in basements. People, you must see what's going on here."

In another video, where you can see a children's playground in the background, an eyewitness says three to four bombs were dropped from a plane. He also says moaning can still be heard from the houses.

A senior US defence official has disclosed the latest assessment of the Russian invasion, as seen by the Pentagon.

The official reports low morale among some Russians, who have yet to establish air superiority after six days and have not yet taken the port city of Mariupol. Some units have surrendered, the official said.

However, Russian troops have taken the nearby port city of Berdyansk, and Melitopol further to the west.

The Pentagon adds that:

• Russia has launched some 400 missiles, but the Ukrainian anti-missile defence system remains viable
• Launchers that could be used for thermobaric weapons have been seen inside Ukraine, but US intelligence cannot confirm if any thermobaric weapons are in the country
• Some 80% of Russian troops that had surrounded Ukraine are now inside the country
• There is indication that some Russian units are running out of food and fuel

Aid is flowing into the country, but establishing a no-fly zone remains outside the possibility of options, the official said.

Image source, Getty Images

Ukrainian President Volodymyr Zelensky has had a 30-minute phone conversation with US President Joe Biden today.

Zelensky wrote on Twitter, external that they discussed anti-Russian sanctions and defence support for Ukraine.

"We must stop the aggressor as soon as possible," he said.

As Russian forces push forward to the Ukrainian capital of Kyiv, we've been hearing from Hanna, who lives in the city.

She has made a bed in a corridor of her flat where she hopes the walls would protect her from shooting or rocket explosions.

"I have electricity here. I put in a table lamp. I have here this suitcase with clothes and all necessary things in case I have to leave," she says.

Hanna took her dog for a walk on Monday night but heard explosions and received a message from the Kyiv administration saying there was a danger of rockets, so she ran home.

"We are scared but honestly I think a lot of people in Kyiv, and all over Ukraine, we’ve started to get used to this.

"A lot of regions around Kyiv are ruined so that is why I’m really afraid about getting food and other products into the city."

She says she is "really afraid" of the large column of Russian military headed towards the capital.

"But Ukrainian armed forces gave me a chance to sleep these two days. Now I believe not in God, I believe in the Ukrainian armed forces," she says.

Lyse Doucet
Chief International Correspondent, Kyiv

As a huge Russian armoured convoy advances on Ukraine's capital, Kyiv, the big question here is how soon it will reach the city's edge.

But this is the sixth day of Russia's invasion and we see not just that armoured convoy, but also the attack close to the TV tower.

There has also been a very serious warning from the Russian defence minister that people should move away from two key security installations.

This applies to people working in those buildings, but also people in the surrounding areas.

Imogen Foulkes
BBC News, Geneva

Russia's foreign minister, Sergei Lavrov, has been treated to a diplomatic boycott at the United Nations in Geneva.

Lavrov, who was addressing both the UN human rights council and the UN conference on disarmament, was greeted with a walkout by Western ambassadors when he began to speak.

He was apparently looking forward to striding the diplomatic stage again in Geneva - Europe's closed airspace put a stop to that.

Instead, when his speech via video link began to play, Western ambassadors walked out - Mr Lavrov spoke to their retreating backs.

Russia's foreign minister then went, virtually, to the UN human rights council. There too the chamber emptied.

The irony: much of Mr Lavrov’s speech was actually about security – or Russia's concept of it.

Amid unfounded allegations that Ukraine might try to acquire nuclear weapons, he said it was time for US missiles in Europe to go home.

Image source, Getty Images

The US secretary of state, Antony Blinken, has questioned Russia’s membership on the UN Human Rights Council in an address to the body.

"One can reasonably ask whether a UN member state, that tries to take over another UN member state - while committing horrific human rights abuses and causing massive humanitarian suffering - should be allowed to remain on this council?", he said

"We must condemn firmly and unequivocally Russia’s attempt to topple a democratically elected government and its gross human rights abuses", Blinken added

He also spoke of Kremlin repression within Russia's own borders, describing the "shuttering of human rights organisations", the harassment of activists and political opponents and media crackdowns.

Ukraine's president has aired his frustration on Twitter over the missile strike on the Babyn Yar Holocaust Memorial Centre in Kyiv.

It is built on Europe's largest mass grave of the Holocaust, where Nazi death squads killed more than 33,000 Jewish people in the space of just two days in 1941.

Volodymyr Zelensky tweeted on Tuesday, external, saying: "What is the point of saying 'never again' for 80 years, if the world stays silent when a bomb drops on the same site of Babyn Yar? At least five killed. History repeating."

BBC Newshour
BBC World Service

A resident of Ukraine's second-biggest city Kharkiv tells the BBC she's hiding out in a bomb shelter with her family, for fear of not knowing where Russian shelling will strike next.

"I'm here with my two children, my husband and other people who live in our [home]", she says, explaining that she occasionally surfaces from the shelter in the city centre to go back to their flat.

She says Ukraine's president is right to call Russia's actions in Ukraine a war crime, adding "it's in all parts of the city".

Ukraine's foreign ministry said Russia was barbaric for attacking a TV tower near a memorial site that commemorates the victims of Babyn Yar.

Babyn Yar was one of the biggest single massacres of Jews during the Nazi Holocaust.

The site contains a a cluster of memorials to remember those who died, including a separate one for the children.

On Twitter, the foreign ministry said "Russian troops fired on the TV tower, near the Memorial complex #BabynYar".

It added: "Russian criminals do not stop at anything in their barbarism. Russia = barbarian."

Image source, Getty Images

If you're just joining us, here are the latest developments so far today:

• The Russian defence ministry warned residents of Kyiv that it was preparing to hit targets in the capital
• A large plume of smoke has risen near the capital city's TV tower - it is unclear if it has been directly hit
• A huge convoy of armoured vehicles is advancing on the city but its progress is hampered by breakdowns, analysts say
• Earlier today a Russian missile hit government offices in Ukraine's second city Kharkiv, killing at least 10 people
• Ukrainian President Volodymyr Zelensky said there were no military targets in the area, and that Russia was committing war crimes
• He addressed the European Parliament via videolink and appealed for EU membership for Ukraine
• The UN refugee agency says more than 660,000 people have left Ukraine so far
• Nato chief Jens Stoltenberg accused Vladimir Putin of "shattering peace in Europe"
• UK Prime Minister Boris Johnson, on a trip to Poland, said the Russian president was engaging in "barbaric and indiscriminate" tactics targeting civilians

Ukrainian emergency services say five people were killed in the Russian attack on the Kyiv television tower.

It's unclear whether the tower itself was hit - it remains standing, but the blast took some broadcasts off air.

BBC Monitoring understands that five more people were injured in the missile strike.

But the 380-metre (1,250ft) TV tower is still standing.

Image source, Reuters