Russia has pounded Kyiv with missiles and drone strikes, killing at least 21 people in one of the largest attacks on Ukraine since war broke out over three years ago.
Ukraine's President Volodymyr Zelensky said the strike early on Thursday, the second-largest attack since Russia launched a full-scale invasion in February 2022, was Moscow's answer to diplomatic efforts to end the conflict.
Prime Minister Sir Keir Starmer condemned the assault, which he said had damaged the British Council building.
"Putin is killing children and civilians and sabotaging hopes of peace," he wrote on X.
The Foreign Office has summoned the Russian ambassador to the UK over the strikes on Kyiv.
Meanwhile, US President Donald Trump "was not happy about this news, but he was also not surprised," White House press secretary Karoline Leavitt said.
US special envoy Keith Kellogg added: "The targets? Not soldiers and weapons but residential areas in Kyiv—blasting civilian trains, the EU & British mission council offices, and innocent civilians.”
Foreign Secretary David Lammy said: “Putin’s strikes last night killed civilians, destroyed homes and damaged buildings, including the British Council and EU Delegation in Kyiv.
“We have summoned the Russian Ambassador.
“The killing and destruction must stop.”
The European Union and the UK summoned Russian envoys to protest. There were no reports of casualties at either site.
Mr Zelensky said the strikes also damaged a Turkish enterprise and the Azerbaijan embassy.
Ms Leavitt told a regular briefing that Mr Trump would have more to say about the strikes later.
"Perhaps both sides of this war are not ready to end it themselves," she said. "The president wants it to end but the leaders of these two countries need it to end and want it to end."
The strikes took place less than two weeks after Mr Trump hosted Russian President Vladimir Putin at a summit in Alaska, a meeting the US President hoped would advance his peace efforts.
"Russia chooses ballistics instead of the negotiating table," Mr Zelensky said on X, calling for new sanctions on Russia. "It chooses to continue killing instead of ending the war."
Russia said its attack had hit military industrial facilities and air bases, and that Ukraine had attacked Russian targets. The Kremlin said it was still interested in pursuing peace talks.
Moscow has regularly denied targeting civilians. Ukrainian officials say scores of civilians have died in Russian strikes on densely populated areas in recent months, and thousands since the start of the war.
During the attack on Kyiv, explosions rang out as clouds of smoke rose into the night sky. Drones whirred overhead.
Mayor Vitali Klitschko described it as one of the biggest attacks on the city in recent months. At least 63 people were wounded in the hours-long assault, which damaged buildings in all city districts, officials said.
Across the country, Ukraine's military said Russian attacks struck 13 locations. National grid operator Ukrenergo said energy facilities were hit, causing power cuts.
A push by Ukraine and its allies to end the invasion has yielded little, despite Mr Trump's meetings this month with Putin then Mr Zelensky.
Russia has stepped up air strikes on Ukrainian towns and cities far behind the front lines and pushed a grinding offensive across much of the east in an effort to pressure Ukraine into giving up territory.
"This is another grim reminder of what is at stake. It shows that the Kremlin will stop at nothing to terrorise Ukraine, blindly killing civilians and even targeting the European Union," EU Commission President Ursula von der Leyen told reporters in Brussels.
She said two missiles had struck near the EU office within 20 seconds of each other.
EU countries are working on how to use frozen Russian assets to help Ukraine, she added.
"We discussed our diplomatic efforts to stop the killings, to end this unprovoked Russian aggression, and to guarantee real security for our people," Mr Zelensky wrote on X after talks with Ms von der Leyen.
Mr Zelensky also said that he had discussed security guarantees for Ukraine with Turkey's President Tayyip Erdogan and they would be set out on paper next week.
Ukraine's military said air defences downed 563 of nearly 600 drones and 26 of 31 missiles launched by Russia across the country.
Russia's Defence Ministry said Russian air defences destroyed 102 Ukrainian drones overnight in at least seven regions.
Ukraine's drone force said it had struck the Afipsky and Kuybyshevskyi oil refineries as part of that attack.
