President Zelensky describes today's talks with Joe Biden as "very fruitful" in a televised joint statement in Kyiv.

President Biden is on his way out of Ukraine and expected to be heading to neighbouring Poland for more diplomatic talks.

Ahead of meetings with Polish President Andrzej Duda, his aide Marcin Przydacz says Biden's visit to Kyiv shows the US is determined to continue to support Ukraine.

Przydacz says in a tweet, external he welcomes the US president's pledge of additional military support because it brings "us significantly closer to peace".

Samantha Granville
Reporting from Kyiv

US National Security Adviser Jake Sullivan has confirmed the presidential delegation did notify Russia about President Biden's trip to Kyiv.

The trip had been in the works for a few months, but a "go" decision was made on Friday.

The White House let the Russians know of the trip a few hours before departure on Sunday morning.

Alice Cuddy
Reporting from Kyiv

We’ve just been speaking to 74-year-old Olha Plaksa and her granddaughter Anastasia.

The pair fled their home in Luhansk, in eastern Ukraine, and dream of one day returning.

They say they have “lost everything” because of the war, and want Ukraine to be given “more support so we can rebuild”.

When asked about the significance of the US president’s visit today, Olha says: “We think it’s for the best.

"The war should be stopped.”

During a press conference in Kyiv earlier, Joe Biden said Russia had attempted to "wipe Ukraine off the map".

Speaking as air raid sirens went off in the capital and across Ukraine, he said that Russian President Vladimir Putin's war of conquest was "failing".

Robin Brant
BBC News

“As long as it takes” is an echo of the mantra, almost precisely the words we heard from German Chancellor Olaf Scholz and French President Emmanuel Macron in recent weeks, and is probably the most important takeaway from this visit.

President Biden was not just addressing his Ukrainian counterpart, but also addressing the people of Ukraine, Vladimir Putin in Moscow and the American people as well.

Remember domestic political support for this is crucial and he was resolute: we stand by Ukraine for as long as it takes.

Zelensky said the negotiations between the two men had been very fruitful.

He talked about how visits over the years had helped to solidify resilience in terms of Ukraine’s position and standing, its confidence now.

Also, Biden’s promise to send M1 Abrams tanks from the US and possible help with long-term missiles would be a great boost to morale on the field for Ukrainian troops.

It is not just about the hardware they are getting: this is about the message it sends and it’s about the confidence they can have.

Image source, Getty Images

Some more reaction to bring you now, this time from Ukraine's foreign minister who believes Joe Biden's visit gives a clear signal to Russia.

Dmytro Kuleba praised the visit as the "victory for the Ukrainian people" and Ukrainian President Volodymyr Zelensky.

Writing on Facebook, Kuleba says the visit was "historic", adding both Biden and Zelensky were pleased with their talks today.

"It [the visit] has been conducted in spite of everything for the sake of Ukraine's victory and all the free world," he says.

Kuleba adds "it is a clear signal to the swamp - no-one is afraid of you!" - presumably a reference to Russia.

President Biden has now departed Kyiv after making an unannounced visit to meet with Ukrainian President Volodymyr Zelensky.

The US leader reaffirmed his country's support for Ukraine, pledging more weapons for Kyiv and promising new sanctions for Russia.

Image source, Getty Images

Image source, Getty Images

Image source, Getty Images

Alice Cuddy
Reporting from Kyiv

People have gathered around St Michael's Golden-Domed Monastery in central Kyiv following US President Joe Biden’s visit there.

Oleksandra Soloviova said she saw a video of Biden on social media and headed to the area to soak up the atmosphere.

“For me, as a regular citizen of Ukraine, I just feel excitement,” the 26-year-old says.

“To me, it’s an important sign for the whole world. For Russia first of all, it shows the US supports us and will continue supporting us, with sanctions and military equipment.”

We're hearing that US President Joe Biden has now left the Ukrainian capital, Kyiv.

He was scheduled to travel to Poland today, but in a surprise visit, arrived in Kyiv to meet Ukraine's President Zelensky this morning.

Chris Partridge
BBC News weapons analyst

We’ve had some more details on those additional $500m (£415m) worth of weapons that Joe Biden has pledged to Ukraine.

The extra artillery ammunition comprises more rockets for HIMARS, the wheeled and highly mobile multiple launch rocket systems that have proved so effective on the battlefield already. They fire precision-guided GMLRS munitions and are accurate to within a few metres at ranges of up to 50 miles (80km).

The anti-armour weapons comprise Javelin missiles to take out tanks and similar vehicles. These shoulder-launched weapons automatically guide themselves to target, striking from the top where the armour is at its weakest.

The key for Ukraine is to continue to weapons-feed their military machine in the east of the country, where Russia is capable of keeping up a high rate of artillery attacks.

Image source, PA Media

It's been a busy start to a week that's likely to only get busier, as Friday marks one year since Russia invaded Ukraine.

Here are the latest developments from Ukraine so far today:

• US President Joe Biden made a surprise visit to Kyiv - his first since the start of the war. Rumours that he might cross the border into Ukraine from Poland, where he was scheduled to make a visit, had been swirling for days
• Biden and Ukraine's Volodymyr Zelensky then appeared alongside each other in central Kyiv and later gave a joint address, in which Zelensky thanked Biden for the "unwavering" support Ukraine had received from the US
• And Biden said he would announce more critical equipment to Ukraine including a $500m weapons pledge

• Meanwhile, EU foreign ministers are meeting in Brussels to discuss the bloc's latest sanctions package against Russia, to be announced over the course of the week
• China's top diplomat, Wang Yi, is in Moscow - a day after US Secretary of State Antony Blinken warned China is considering giving Russia "lethal support" in the shape of weapons and ammunition

Defence and security expert at the University of Bath and former Nato analyst, Dr Patrick Bury, has said the main takeaway from Biden's meeting is the commitment from Nato allies that “we are in this for the long run”.

Speaking to BBC News, he said: “They are signalling to Vladimir Putin that basically we are in this and are not going to back down and therefore you are going to have to question your fundamental assumptions about trying to outlast us in this war.”

Bury also spoke about Biden making a surprise visit today rather than on the one year anniversary on 24 February.

He said: “In terms of the timing, they probably didn’t want to send the president on the anniversary because of the increased risks of Russian bombardment that day.

“It would have been planned for a good while, these visits, they take a lot of security planning of course, and it was probably discussed or even mooted before when Zelensky visited the US back in December.”

US President Joe Biden has met Ukrainian President Volodymyr Zelensky in Kyiv during a visit that was shrouded in secrecy until this morning.

He also met the First Lady of Ukraine, Olena Zelenska, as you can watch below.

Alice Cuddy
Reporting from Kyiv

I have been speaking to people on the streets in Kyiv about their reactions to the US president’s visit.

Lawyer Roksoliana Gera told us she was “really surprised” when she crossed the street and caught a glimpse of Joe Biden.

“I’m so grateful for his support. It means so much to us,” she says. “I appreciate his courage, that he took on this challenge and came to show the support of the American nation.”

Roksoliana said she was particularly grateful that he had chosen today – the Day of the Heavenly Hundred Heroes – to visit.

The day commemorates the more than 100 people killed nine years ago when the government of pro-Russian President Viktor Yanukovych was overthrown in what's known as the Revolution of Dignity.

“On this day, when we are trying to remember all the defenders of Ukrainian liberty in 2014, it’s a good sign for us,” she says.

“It’s such a historical day,” she says of Biden’s visit

Image source, Getty Images

In his speech alongside President Zelensky, President Biden commended Ukraine's courage during the war, while noting he had visited Kyiv six times when he had earlier served as vice president.

"I knew I would be back," he said.

"Putin thought Ukraine was weak and the West was divided... he’s counting on us not sticking together. He was counting on the inability to keep Nato united. He was counting on us not to be able to bring in others to the side of Ukraine.

"He thought he could outlast us. I don’t think he’s thinking that right now. He’s just been plain wrong."

The air raid sirens wailed while Zelensky and Biden were inside St Michael's Golden-Domed Cathedral in central Kyiv.

Earlier, Biden said Washington would provide Kyiv with a new military aid package worth $500m that would be announced tomorrow.

Important air surveillance radars part of new US weapons pledgepublished at 11:05 Greenwich Mean Time 20 February 2023

11:05 GMT 20 February 2023

Chris Partridge
BBC News weapons analyst

The United States has repeatedly stated that it will help Ukraine with weapons for as "long as it takes" and what Joe Biden is saying this morning after he turned up in Kyiv with the Ukrainian president further reinforces that commitment.

While there are no specifics on the detail, we do now know from a White House statement that more artillery ammunition is being pledged, along with anti-armour systems ahead of a possible new ground offensive by Russia.

In addition, the provision of air surveillance radars points to the critical need for protection against Russian cruise missiles and other air-launched precision munitions – as well as Russian aircraft. These radars will give additional warning to the Ukrainian military of any air attacks.

Again no mention of Western jets, perhaps unsurprisingly as President Biden already ruled out sending F-16s from the US to Ukraine, given the complexities of such a move.

To date, the United States has committed $30bn in security assistance to Ukraine and it seems it won’t be ending anytime soon.

In a televised joint statement, flanked by Biden, Zelensky says that the "democratic world" has to "win this historic fight".

"It's the most important visit of the whole history of US-Ukraine relations," Zelensky says, adding that it "underlines the results we have already achieved".

"Today our negotiations were very fruitful," Zelensky says.

He adds that the results of this visit will surely be seen and have a reflection on the battlefield. The US decision to give Abrams tanks to Ukraine earlier in January has already contributed to reinforcing Ukraine's defence, Zelensky says, adding that he and Biden also talked about long-range weapons.

"I know there will be a very signfiicant package of support to Ukraine... serving a clear signal that Russia's aggression has no chance," Zelensky says.

"Ukraine is grateful to you, Mr President" he says to Biden.

Image source, EPA

Ahead of a press conference, Joe Biden sat down for a chat with Volodymyr Zelensky and said he was “looking forward to discussing the world” with him.

He also praised the citizens of Ukraine for their “heroic” fighting – despite a lack of military experience.

He said: “Again the admiration for the people of Ukraine, ordinary, hardworking citizens, who had never trained in the military, but the way they stepped up is just beyond heroic and the whole world thinks so.”

Image source, Getty Images

Biden's secret trip to Ukraine was made via train from the border of Poland, the New York Times reports.

The visit to Kyiv remained a secret because of security concerns. Reports also say that that Biden departed Washington without notice after he and his wife Jill had a rare dinner out at a restaurant on Saturday night.

Officials had denied that Biden would visit Ukraine during his scheduled to trip to eastern Europe.

The New York Times says: "Indeed, the White House on Sunday night issued a public schedule for Monday showing the president still in Washington and leaving in the evening for Warsaw, when in fact he was already half a world away."