Donald Trump yesterday called on Vladimir Putin to halt attacks on Ukraine, in a rare rebuke of the Russian leader after Moscow fired a barrage of missiles and drones at Kyiv, killing at least 10 in the deadliest attack on the capital in months.
The direct appeal to Putin came after Ukrainian President Volodymyr Zelensky urged his allies to put Russia under more pressure to halt its invasion.
The Ukrainian leader cut short a trip to South Africa to deal with the aftermath of the deadly strikes, the latest in a wave of large-scale Russian aerial attacks that have killed dozens of civilians.
"I am not happy with the Russian strikes on KYIV," Trump said on social media.
"Not necessary, and very bad timing. Vladimir, STOP!" he said. "Lets get the Peace Deal DONE!"
Trump's envoy Steve Witkoff is due in Russia this week where he is expected to hold talks with Putin on a possible deal, his fourth since Trump returned to the White House in January.
Ukraine has been battered with aerial attacks throughout Russia's three-year invasion but deadly strikes on Kyiv, better protected by air defences than other cities, are less common.
The attacks threw more doubt on already fraught US efforts to push Russia and Ukraine to agree to a ceasefire, with Trump having lashed out at Zelensky this week for not being willing to accept Russian occupation of Crimea, annexed by Moscow in 2014.
"We do everything that our partners have proposed, only what contradicts our legislation and the Constitution we cannot do," Zelensky told reporters in South Africa in response to a question about Crimea.
Zelensky also questioned whether Kyiv's allies were themselves doing enough to force Putin to agree to a full and unconditional ceasefire.
"I don't see any strong pressure on Russia or any new sanctions packages against Russia's aggression," Zelensky said, highlighting that Trump had previously warned of repercussions if Moscow did not agree to pause the fighting.
"The strikes must be stopped immediately and unconditionally," Zelensky said, calling this morning's aerial assault "one of the most sophisticated, most brazen" of the entire war.
Loud blasts sounded over the Ukrainian capital at around 1:00am (2200 GMT) after air raid sirens rang out across Kyiv, AFP journalists on the ground said.
Russia fired at least 70 missiles and 145 drones at Ukraine between late Wednesday and early tody, the main target being Kyiv, the Ukrainian air force said.
Rescuers this afternoon said 10 people were killed and 90 injured.
Russia said it had targeted Ukraine's defence industry, including plants that produced "rocket fuel and gunpowder".
Olena Davydiuk, a 33-year-old lawyer in Kyiv, told AFP she saw windows breaking and doors "falling out of their hinges" during the barrage.
"People were being pulled out of the rubble. They said that there were dead people there too," she added.
In the Sviatoshinsky district in the west of Kyiv, an AFP journalist saw a body bag with one of the victims lain out on a strip of grass.
A woman sat on a small folded-out chair stroking the arm of another person killed in the attack, the body covered in a striped blue sheet.
Moscow's army has launched some of its most deadly aerial strikes at Ukraine over the last month -- defying Trump's push to bring about a rapid end to the bloodshed.
A ballistic missile strike on the centre of northeastern city of Sumy killed at least 35 on April 13.
And an attack on Zelensky's home town of Kryvyi Rig in early April killed at least 19 -- including nine children after a missile slammed into a residential area near a children's playground.
Trump had on Wednesday accused Zelensky of frustrating peace efforts by ruling out recognising Russia's claim over Crimea, a territory the US president said was "lost years ago".
Russia annexed the Black Sea peninsula in 2014 and then backed rebels in eastern Ukraine.
Asked about Trump's comments the Kyiv had "lost" Crimea, Kremlin spokesman Dmitry Peskov told reporters today: "This completely corresponds with our understanding, which we have been saying for a long time."