Donald Trump has told Vladimir Putin to spare the lives of “thousands of Ukrainian troops” surrounded by Russian forces in Kursk.

It came after Putin said on Thursday that Ukrainian troops in the region, which was invaded by Kyiv last summer, had two choices: “Surrender or die”.

The US and Russia are locked in talks over a temporary truce to which Ukraine has already agreed.

Mr Trump said “we had very good and productive discussions” in Moscow, where Steve Witkoff, the president’s envoy, met the Russian leader.

The US president said Kyiv’s troops were in a “very bad and vulnerable position” and he “strongly requested to President Putin that their lives be spared”.

“This would be a horrible massacre, one not seen since World War Two,” he said.