U.S. President Donald Trump said he would speak to Russia's Vladimir Putin on Tuesday morning about ending the Ukraine war, with territorial concessions by Kyiv and control of the Zaporizhzhia nuclear power plant likely to feature prominently in the talks.

"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," Trump told reporters in Washington on Monday. Trump has been trying to win Putin's support for a 30-day ceasefire proposal that Ukraine accepted last week, as both sides traded heavy aerial strikes early on Monday and Russia moved closer to ejecting Ukrainian forces from their months-old foothold in the western Russian region of Kursk.

Trump said Ukrainian soldiers in the Kursk region were "in deep trouble," surrounded by Russian soldiers. He said his freeze on military aid to Ukraine earlier this month and his contentious Oval Office meeting with Ukrainian President Volodymyr Zelenskyy may have helped persuade Kyiv. "A lot of people are being killed over there, and we had to get Ukraine to do the right thing," he said. "But I think they're doing the right thing right now."