US President Donald Trump says he will speak with Russian President Vladimir Putin in a call on Tuesday. He has been trying to get Moscow to sign on to a US plan for a ceasefire in Ukraine.

Speaking to reporters on Monday at the Kennedy Center in Washington, Trump said: "What's happening in Ukraine is not good. But we're going to see if we can work a peace agreement, a ceasefire and peace. And I think we'll be able to do it. I'm speaking to President Putin tomorrow morning."

This follows comments Trump made aboard Air Force One on Sunday, saying that the two leaders would discuss land, power plants, and "dividing up certain assets."

White House Press Secretary Karoline Leavitt says they have never been closer to a peace deal. She also confirms that Trump will address a nuclear power plant "that is on the border" with the Russian leader.

The Kremlin spokesperson, Dmitry Peskov, says preparations for the conversation are underway, but did not give further details.