We are turning to the White House now as US President Joe Biden gives a statement on the Ukraine crisis and America's response.

Russian helicopters nearing Kyiv have been fired upon by Ukrainian troops.

The video shows heavy gunfire striking the aircraft as they pass over Vyshhorod, an area just north of the Ukrainian capital.

It has been verified by the BBC, however the source of the video is unknown.

Image source, Getty Images

Things continue to move fast as Russian forces launch a full-scale assault on Ukraine. Here's the latest from on the ground:

• There is fighting on the outskirts of the Ukrainian capital, Kyiv, as government forces try to recapture an airbase and airport after Russian airborne troops took control of it
• Ukraine President Volodymyr Zelensky has vowed that they will re-take the airport and push back Russian troops
• The port city of Mariupol is under heavy fire with reports of hundreds of explosions
• The UN High Commissioner for Refugees tells the BBC he estimates that more than 100,000 people have already left their homes in Ukraine, with thousands crossing into Moldova and Romania
• Russian police have detained more than 700 people at anti-war protests across Russia, an independent monitor says
• There has been fierce fighting around the site of the former nuclear power plant in Chernobyl, with Russian forces capturing it
• UK Prime Minister Boris Johnson has outlined more sanctions against Russia, including all major Russian banks facing a full UK asset freeze and a list of oligarchs being sanctioned

Russia has launched a full-scale attack on Ukraine, and there are fears it could soon move on Kyiv, the capital.

Watch this video to see how the day has unfolded.

Ukraine's port city of Mariupol is under heavy fire with reports of hundreds of explosions, a diplomatic source has told Reuters news agency.

Mariupol is one of the biggest Ukrainian ports on the Azov Sea and is located near a frontline held by Russian-backed separatists in the Donetsk region - which Vladimir Putin has recognised as an independent state.

Taking Mariupol would help Russia secure a direct land route to Crimea, the Ukrainian peninsula annexed by Russia in 2014.

Image source, Getty Images

At least 735 people have been arrested at anti-war protests across Russia today following the invasion of Ukraine, an independent monitor says.

Demonstrators were detained in 40 cities, according to OVD-Info, which tracks arrests at opposition rallies.

More than 330 people have been detained in Moscow, it says.

Images have emerged of Russian police detaining protesters at an anti-war protest taking place in central Moscow's Pushkinskaya Square.

An image taken by an AFP photographer at the scene shows officers detaining a man holding a placard which reads: "No to war with Ukraine! Putin to resign".

Image source, AFP via Getty Images

Other images show officers blocking-off the square. A Guardian reporter at the scene said on Twitter that there is a "very heavy police presence" in the area.

In the US, a pro-Ukraine rally is expected to take place outside the White House in Washington DC at 16:30 local time (21:30 GMT).

There is fierce fighting around the site of the former nuclear power plant in Chernobyl.

Ukrainian presidential adviser Mykhaylo Podolyak has said it is impossible to say if the site is safe.

Podolyak says: "After a fierce battle, we lost control of the Chernobyl site."

A video, verified by the BBC, appears to show Russian tanks stationed outside the former nuclear power station.

Chernobyl was the site of one of the worst nuclear disasters in history, when one of its four reactors exploded in 1986.

If you're just joining us in the UK, we have special coverage about to start at 18:00 GMT on BBC One and BBC iPlayer with an extended BBC News at Six.

Clive Myrie is live from Kyiv in Ukraine, our correspondents are dotted around the country and Steve Rosenberg reports from Moscow on a momentous day.

You can watch that live on BBC iPlayer (UK only)

Later tonight, Mark Urban is presenting an extended Newsnight at 22:30 on BBC Two. You can also watch that on iPlayer.

You can also listen to the BBC World Service for all the latest, 24 hours a day.

And of course we will continue to bring you rolling coverage here on the BBC website and app.

Tara McKelvey
BBC News, Washington

Ukraine's ambassador in Washington has said the country does "not expect anyone" to fight for the country as it battles Russian forces.

Speaking to reporters at the Ukrainian embassy, Oksana Markarova said that "Kyiv is fully in [government] control" but that Russian helicopters are "just outside" of the city.

"The situation is very tense," she added.

According to Markarova, dozens of Ukrainian military personnel had been killed as of Thursday morning.

Paul Adams
BBC diplomatic correspondent, in Kyiv

Image source, Getty Images

On the street bounded by the golden domes of St Sophia’s and St Michael’s cathedrals, it’s dark and surreal.

Jets are flying overhead intermittently and there’s an acrid smell in the air. It smells like burning papers.

Three soldiers came by, looking for a man with a drone. Everyone is on edge.

The buses are still running, but I can see barely any passengers.

Jessica Parker
BBC political correspondent

It is understood the EU could suspend part of its visa facilitation agreement with Russia in its latest sanctions package.

Sources have indicated that it would affect new arrivals and those “linked to the [Russian] regime” - such as officials, diplomats and the military.

On calls to cut Russia off from the financial messaging service Swift, one senior diplomat said that while the idea was “out there”, it wasn’t the focus for now.

Swift allows quick transactions and is used by 11,000 financial institutions in 200 countries.

But if it’s not in the upcoming EU package, they said, that “doesn’t mean it’s off the table".

Officials have indicated that the package is likely to include measures on export controls, the financial and industrial sectors.

Labour leader Sir Keir Starmer is now speaking. He says the Russian people, as well as those of Ukraine, will suffer, having been "plunged into chaos by a violent elite".

And the UK will suffer economic pain because of sanctions, but this is a necessary "sacrifice" to stop Vladimir Putin, he adds.

Ukraine needs weapons, as well as humanitarian help, Starmer argues.

He also calls for a full overhaul of the UK's financial system to target oligarchs' investments.

These are the sanctions Prime Minister Boris Johnson has just announced the UK will put on Russia:

1. All major Russian banks will have their assets frozen and will be excluded from the UK financial system. This will stop them from accessing sterling and clearing payments through the UK. This includes a full and immediate freeze of VTB bank
2. Legislation will stop major Russian companies and the state from raising finance or borrowing money on UK markets
3. Asset freezes will be put on 100 new individuals or entities
4. The Aeroflot airline will be banned from landing in the UK
5. There will be a suspension of dual use export licences to cover things which can be used for military purposes
6. Within days the UK will stop exports of hi-tech items and oil refinery equipment
7. There will be a limit on deposits Russians can make to UK bank accounts
8. He says there is potential to cut Russia out from Swift payments and "nothing is off the table"
9. Similar financial sanctions will be extended to Belarus for its role in the assault on Ukraine
10. The UK will bring forward parts of the economic crime bill before the Easter recess

The UK will work with allies to target Russian finances, Boris Johnson tells the House of Commons.

Russia's shares are falling fast, with the rouble plummeting to record lows against the dollar, he says.

The PM then promises to counter "the Kremlin's blizzard of lies and disinformation".

Nato's defences must be strengthened and the leaders of member nations will meet on Friday, he adds.

Boris Johnson says there will be limits on the amount Russians can deposit in UK banks, with asset freezes extended to around 100 more people.

Airline Aeroflot will be banned from the UK, he says, while there will be "stringent export controls" for technology sold to Russia.

Similar measures will be imposed on Belarus, the PM says.

"Oligarchs in London will have nowhere to hide," he adds.

Image source, HOC

UK Prime Minister Boris Johnson begins outlining the latest sanctions against Russia, saying Ukrainians are offering a "fierce defence" and calling Vladimir Putin a "bloodstained aggressor".

He announces that all major Russian banks will face a full UK asset freeze.

The prime minister also promises legislation next week to stop large Russian companies raising finance/debt on UK markets.

The UK prime minister is about to announce new sanctions.

On the ground, the Ukrainian military say they have launched an artillery attack on Russian paratroopers who have landed at Antonov Airport near Kyiv and tried to take control.

The airport, which is a significant international cargo port and also a military base, is about an hour and a half's drive from Kyiv.

The fighting there is understood to be the closest that Russian forces have managed to get to the Ukrainian capital on the first day of their invasion.

In the next few minutes we will hear what sanctions the UK will put on Russia following its invasion of Ukraine.

UK Prime Minister Boris Johnson will make a statement in the House of Commons at around 17:00 GMT.

After that, US President Joe Biden plans to make his first public remarks on the new conflict in Ukraine at 17:30 GMT, the White House says.

Meanwhile, Ukraine's ambassador to the US is calling for Russia to be cut-off from the Swift money transfer system.

Image source, AFP via Getty Images

Things are moving fast in Ukraine so here's a re-cap of the latest developments on the ground and reaction to Russia's invasion. Much of the information coming from both sides remains unverified but it is clear that Russia is mounting a major assault.

Russian missile strikes and explosions have been reported near major cities and targeting military infrastructure. Russia says it has destroyed more than 70 military targets.

The Ukrainian military claims to have shot down at least six Russian aircraft but this has not been confirmed.

Fierce fighting is reported in the east, where Russian forces are said to have attacked a hospital in the Donetsk region. There have been clashes in the port cities of Odesa and Mariupol, and in Kharkiv, in the north-east.

Russia appears to be in control of the Antonov airbase, around 15-20 miles outside Kyiv. But Ukraine says it is fighting back and a battle appears to be continuing there.

The number of overall casualties continues to be unclear. Dozens of military personnel and civilians are reported killed.

In the capital, Kyiv, air-raid sirens are sounding. Mayor Vitali Klitschko, a former heavyweight boxing champion, has imposed a curfew on the city from 22:00 to 07:00 local time.

UK PM Boris Johnson is to announce further sanctions on Russia at 17:00 GMT. The EU will also freeze Russian assets and target Kremlin "interests" in new sanctions to be announced later.

And US President Joe Biden is due make an address on Ukraine at 12:30 ET (17:30 GMT).

James Waterhouse
Kyiv correspondent, BBC News

Image source, AFP

President Zelensky has again spoken to the people of Ukraine this afternoon, swapping his dark suit for a military uniform.

In his latest address he compares the fighting to the "sound of the new iron curtain that’s falling and closing Russia from the civilised world", adding "our task is for that curtain not to fall on Ukrainian territory."

He's spoken about an operational pause and claims Ukrainian forces have been successfully defending the eastern Donbas region, as well as fighting near Kharkiv.

Zelensky says the most problematic area is in Kherson in the south of the country, where Russian troops have moved north from annexed Crimea.

In the north, he says the enemy is continuing to push into region, and he's described heavy fighting at Chernobyl.

He also talks about troop losses as well as captured Russian soldiers.

Zelensky says lots of Russian aviation and vehicles have been destroyed, we see that many Russians are shocked with what’s happening.