Russian President Vladimir Putin and US President Donald Trump's top negotiator failed to make any changes to the Ukraine peace deal after five hours of talks.

A Kremlin spokesman said the Moscow meeting was "constructive" but parts of the plan were unacceptable to Russia.

Trump's special envoy, Steve Witkoff, and Trump's son-in-law, Jared Kushner, met with Putin after weeks of intense diplomatic talks that were said to be aimed at ending the war.

The US delegation did not comment after leaving Moscow.

Earlier on Tuesday, Putin said that changes to the US-backed peace plan, which is backed by Kiev and Europe, were unacceptable.

He added that "if Europe wants to go to war and starts, we are ready now."

Ukraine and its allies have been pushing the White House to revise the peace plan.

The Kremlin had previously announced that the Russian side had not accepted the plan before the revisions to the peace agreement were made.