$TRUMP US President Donald Trump has said he is "not happy" with deadly Russian strikes on Kyiv and that President Vladimir Putin should "stop" - but has not said if further action might be taken against Russia.

Overnight into Thursday, the attacks on the Ukrainian capital killed at least 12 people and injured 90 others.

The US president said he is "putting a lot of pressure" on both sides to end the war in Ukraine, following the deadliest attacks Kyiv has seen since last July.