Ukrainian President Volodymir Zelensky says he expects more prisoners of war will be exchanged with Russia following today's round of peace talks in Istanbul
Speaking after a Nato meeting in Vilnius, he reiterates support for a new set of sanctions to pressure President Vladimir Putin into agreeing to a ceasefire
The head of the Ukrainian delegation confirms Russia has now handed over a memorandum outlining its negotiation demands, saying a potential meeting between Zelensky and Putin has also been discussed
Russia says they've agreed to return the remains of 6,000 soldiers and offered a two to three day ceasefire on certain parts of the frontline to facilitate the collection of the bodies
Today's talks are unlikely to yield a breakthrough but Russia and Ukraine both want to avoid straining their ties with the White House, writes the BBC's Liza Fokht from Istanbul
We've just heard that the Russian delegation, headed by Kremlin aide Vladimir Medinsky, has now arrived in Istanbul for today's talks with Ukraine.
Ibrahim Kalin, director of Turkish intelligence service MIT, has also just arrived.
We'll bring you the latest updates as we get them.
Russia’s Foreign Minister Sergei Lavrov spoke to US Secretary of State Marco Rubio over the phone yesterday, Moscow says.
In a statement on the messaging app Telegram, Russia’s ministry of foreign affairs says the officials “exchanged views on various initiatives related to a political settlement of the Ukraine crisis”, including today’s talks.
Separately, according to Russian news agency Tass, Lavrov has said Moscow is ready to present a memorandum on “all aspects of reliably overcoming the root causes of the crisis” to Ukrainian officials today.
Vitaliy Shevchenko
Russia editor, reporting from Istanbul
With just hours before the talks in Istanbul, Russian artillery attacked the southern Ukrainian city of Kherson, killing a man who happened to be out in the street at the time of the attack, local authorities say.
A five-year-old boy suffered blast injuries and concussion, according to local official Oleksandr Prokudin.
Ahead of today's planned talks between Ukraine and Russia, we've been hearing reports of attacks from both sides continuing overnight.
Russia's Military of Defence says they intercepted more than 160 Ukrainian drones between 20:10 and 02:00 local time.
Kursk, Belgorod and Lipetsk were among the regions that were targeted, the military says.
Ukraine's armed forces this morning says overnight air strikes from Russia were aimed at regions including Kharkiv and Donetsk.
As of 08:30 local time (06:30 BST), Ukraine's air defence had intercepted 52 out of 84 drones and missiles launched by Russia, it says.
Hits were recorded in 12 locations, the armed forces adds.
Vitaliy Shevchenko
Russia editor, reporting from Istanbul
The strategic bombers hit by Ukraine yesterday are not just tools of war, they are symbols of Russia’s nuclear might and strategic invulnerability.
For decades, Moscow has been sending such bombers on missions across the globe to project an image of a nuclear superpower not to be messed with.
Now that image has been badly damaged by homegrown Ukrainian drones costing peanuts.
Paul Kirby
Europe digital editor
When Russian President Vladimir Putin ordered up to 200,000 soldiers into Ukraine, his aim was to sweep into the capital, Kyiv, in days, overthrow its pro-Western government and return Ukraine to Russia's sphere of influence.
Putin failed but, more than three years on, a fifth of Ukrainian territory is in Russian hands.
Image source, ReutersPresident Putin speaking at a security council meeting in February
Launching the biggest European invasion since the end of World War Two, Putin gave a fiery speech on TV declaring his goal was to "demilitarise and denazify" Ukraine.
Russia has repeatedly painted modern Ukraine as a Nazi state, in a crass distortion of history.
Putin had already seized Ukraine's Crimean peninsula eight years earlier, after a revolution that ousted Ukraine's pro-Russian president and replaced him with a more pro-Western government.
Putin then triggered a lower-level war in Ukraine's eastern Donbas region, with pro-Russian proxy forces occupying territory and setting up rebel states supported by Moscow.
But the 2022 invasion was on a different scale.
Image source, MARCUS YAM/LOS ANGELES TIMESUkrainians sought shelter in underground shelters as Russian forces attacked on 24 February 2022
Putin has for years complained about Nato's eastward expansion as a security threat, and sees any possibility of Ukraine joining the alliance as a major red line.
It is part of Ukraine's constitution to join the European Union and Nato, but there was no real prospect of this when the full-scale war began.
Putin's grievance against Nato dates back to 1990, when he claims the West promised not to expand "an inch to the East".
However that was before the Soviet Union collapsed and it was based on a limited commitment made to then Soviet President Mikhail Gorbachev.
We've heard that the meeting between the Turkish, Russian and Ukrainian delegations is planned to start at 13:00 local time (11:00 BST), according to the Turkish foreign ministry.
The talks will be chaired by Turkey's Minister of Foreign Affairs Hakan Fidan, the foreign ministry also says.
Vladimir Medinsky, a presidential aide, is leading the Russian delegation, he also represented Moscow at the talks in May. The Ukrainian side is headed by its Defence Minister Rustem Umerov.
Vitaliy Shevchenko
Russia editor, reporting from Istanbul
Ukrainians know you can only negotiate with Putin from a position of force – hence the attack on Russia’s strategic aviation the day before the talks in Istanbul.
The timing also suggests they probably think there’s value in talking to someone like Russian presidential aide Vladimir Medinsky, if sending a message to him was part of the plan.
Hugo Bachega
Reporting from Istanbul
After more than three years of war, Russia and Ukraine remain far apart, and few expect a breakthrough in the second round of direct talks in Istanbul.
Russia has, so far, rejected Ukraine’s call for an unconditional ceasefire before discussing the terms of a long-term truce.
Image source, Getty ImagesTop officials from the US and Russia met in Riyadh in February in the first such summit for years
Russia has not made public its conditions ahead of today’s meeting, but officials have continued to voice demands already rejected by Ukraine, including limiting the size of the Ukrainian army and recognition of Ukrainian territory seized by Russia, including Crimea.
Ukrainian officials have accused Russian President Vladimir Putin of delaying tactics in the negotiations, and some suspect he is not really interested in pausing or ending the conflict.
Russia has intensified its attacks on Ukraine in recent weeks, and Ukraine says there are signs Russia is planning a summer offensive, to try to capture more Ukrainian land.
Image source, Office of the President of Ukraine via Getty ImagesTrump and Zelensky spoke face-to-face on the sideline of Pope Francis's funeral at the Vatican in April
Both sides are under pressure from President Trump to reach a deal and are keen to show they back his efforts: Ukraine, which wants the violence to stop, needs American military aid, while Russia hopes to see the easing of economic sanctions.
The first round of talks resulted in little more than a prisoner exchange deal.
Sunday’s large-scale Ukrainian attack on air bases deep inside Russia is a message from Ukraine to Russia and the West: the country is still fighting and is unlikely to make concessions it considers unacceptable.
We've just seen an update on the messaging app Telegram from Andriy Kovalenko, who is the head of Ukraine's Centre for Countering Disinformation.
He says at least 13 Russian aircraft were destroyed by Sunday's drone attack and adds that other military planes were damaged.
As we reported earlier, Ukraine claimed to have hit more than 40 Russian bombers yesterday, in one of the most audacious attacks so far on Russian aviation.
Vitaliy Shevchenko
Russia editor, reporting from Istanbul
The night before the talks, Russia attacked Ukraine with 80 drones, three ballistic missiles and one cruise missile, Ukraine’s Air Force says.
According to the military, 52 of the drones were intercepted or lost without causing any damage.
The number of drones used by Russia last night is much lower than the record-breaking amount (472) the night before.
Officials from Kyiv and Moscow met in Istanbul just last month for their first face-to-face talks in three years.
While the brief meeting saw them agree to swap 1,000 prisoners of war, it yielded little else in terms of bringing the war to an end.
Neither Russia’s President Putin nor Ukraine’s President Zelensky were in attendance. The latter criticised the delegation sent from Moscow as “low-level”.
US President Donald Trump was also absent despite being initially expected to attend - and said at the time that no significant progress could be expected until he and Putin met.
After the talks, the leader of Russia’s delegation Vladimir Medinsky said he was “satisfied”.
He said Russia had "taken notice" of Ukraine's request for direct talks to take place between Putin and Zelensky, and that both sides would present their “vision of a possible future ceasefire".
But a Ukraine foreign ministry spokesperson said the Kremlin made "new and unacceptable demands" - including insisting Kyiv withdraw its troops from large parts of its own territory, he said, in exchange for a ceasefire.
Vitaliy Shevchenko
Russia editor, reporting from Istanbul
This is where the talks will be happening - the lavish surroundings of Ciragan Palace in Istanbul.
We've just seen an update that Ukraine's delegation has arrived in Istanbul for the latest round of peace talks with Russia, according to Heorhii Tykhyi - a spokesperson for Ukraine's foreign ministry.
We'll bring you the latest updates and analysis as we get it throughout the day.
Footage that appears to show the moment planes were set on fire at a military airbase on Sunday has been shown to the Reuters news agency by a Ukrainian security source.
The pictures in this short clip appear to have been filmed by a drone:
Watch: Video appears to show drone attack on Russian planes
Jack Burgess
Live page editor
Yesterday's major drone attack by Ukraine on several Russian military airbases left more than 40 Russian bomber planes "burning", according to the Security Service of Ukraine (SBU).
"Operation Spider’s Web” took one year-and-a-half to organise and was personally overseen by Ukrainian President Volodymyr Zelensky, the SBU said.
Sources said the drones were launched from trucks after being smuggled into Russia, stored on wooden pallets, loaded on to trucks, driven to distant airbases and launched remotely.
"Ukraine has conducted audacious attacks on Russia before - but this is a new level," said the BBC's diplomatic correspondent Paul Adams, writing from Kyiv.
Moscow has said Ukraine carried out a "terrorist attack" in five regions but claimed they were "repelled" and added that multiple participants had been arrested, according to Russia's defence ministry.
Meanwhile, the weekend also saw the largest-ever aerial attack on Ukraine, as Russia continues its strikes, more than three years after Russian President Vladimir Putin launched a full-scale invasion of Ukraine in February 2022.
Barbara Tasch
Live editor
Ukraine and Russia are due to hold a second round of direct talks in Turkey today. Both countries have confirmed they have sent delegations to Istanbul.
Last month, the two countries held a first round of talks that brought no breakthrough, but achieved a prisoner of war swap.
Ukrainian President Volodymyr Zelensky has said Moscow is "doing everything it can to ensure the next possible meeting is fruitless" and also noted Russia had not provided its negotiation proposals before the meeting.
The talks come after Kyiv conducted "Operation Spider’s Web" over the weekend, launching 117 drones in an attack on Russian airbases, which our diplomatic correspondent has called one of Ukraine's "boldest attacks so far".
The Security Service of Ukraine (SBU) claims the attack struck 34% of Russia’s strategic bombers capable of carrying cruise missiles. The operation followed the largest-ever aerial attack on Ukraine by Russia the previous night.
Stay with us as we bring you the latest developments and analysis from Istanbul and the Ukrainian front.
Video appears to show Ukraine drone attack in Russia
A swarm of Ukrainian drones have attacked a number of military airbases deep inside Russia’s borders and left more than 40 bomber aircraft in flames, according to Ukrainian officials.
Sources say FPV drones were smuggled into Russia, along with mobile wooden cabins. The cabins were carried by trucks with the drones hidden inside. The cabin roofs opened remotely - and then the drones took off and zoned in on the nearby bases.
Ukrainian President Volodymyr Zelensky described the operation as "an absolutely brilliant result" and said the Ukrainians' actions will "undoubtedly be in the history books".
He said planning for the operation began 18 months ago, and those involved “were withdrawn from Russian territory in time".
Moscow said Ukraine carried out a "terrorist attack" in five regions but they were "repelled". Russia's defence ministry added multiple participants in the operation had been arrested.
Russian and Ukrainian officials are due to meet in Istanbul tomorrow but, as BBC Monitoring's Russia editor Vitality Shevchenko writes, these attacks "won't necessarily alter the course of talks".
We're pausing our live coverage but you can stay across this story on BBC News.
Vitaliy Shevchenko
Russia editor, BBC Monitoring
Last night saw the largest-ever aerial attack on Ukraine, followed by Ukraine's daring raid on bombers deep within Russian territory.
This shows that Russia is as keen to attack Ukraine as ever, and, in turn, President Zelensky is keen to prove wrong those who think - to use Donald Trump's phrase - that he has "no cards".
Extraordinary developments, but they won't necessarily alter the course of talks on Monday. The people attending them are there to deliver and hear messages, but not to make big decisions.
All we know is that in the absence of progress on the diplomatic front, both Ukraine and Russia are more than willing to let the drones and missiles do the talking.
Paul Adams
Diplomatic correspondent, reporting from Kyiv
Far from Ukraine’s borders, an attack of astonishing audacity.
Russian strategic bombers picked off, one by one, by a fleet of tiny drones. Ukraine is calling this Operation Spider’s Web. Personally overseen by President Zelensky, it’s one of Kyiv’s boldest attacks so far.
A reminder, despite Russia’s overwhelming strength in numbers, that Ukraine is a resourceful, determined enemy.
Sources say it took a year and a half to prepare. Dozens of drones, smuggled into Russia. Stored on wooden pallets. Loaded onto trucks. Driven to distant airbases and launched remotely.
Swarms of drones were picked up on social media videos recorded from Siberia to the Arctic circle.
In one video, filmed at a petrol station north of Irkutsk, drones can clearly be seen taking off from a parked truck. And there’s gunfire, as police officers desperately try to bring it down.
With smoke rising from bases across Russia, Ukrainian sources said they had done $2bn (£1.5bn) worth of damage - a claim impossible to verify.
Earlier, it was Ukraine counting the costs.
Cities, including Zaporizhzhia, were targeted in another major drone and missile attack. Twelve Ukrainian soldiers were killed at a training base, leading the head of Ukraine’s land forces to tender his resignation.
What chance, then, for another round of peace talks, due to take place in Istanbul tomorrow?
Russian and Ukrainian delegations are expected to be there - but after 24 hours of mayhem, the omens for a breakthrough do not seem good.