US President Donald Trump said he would speak to Russia's Vladimir Putin 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.

"We want to see if we can bring that war to an end," Trump told reporters on Air Force One during a flight to the Washington area from Florida. "Maybe we can, maybe we can't, but I think we have a very good chance.

"I'll be speaking to President Putin on Tuesday. A lot of work's been done over the weekend."

"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 said.

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 Zelensky 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."

Damage in the Kursk region. – Reuters

Zelensky, in his nightly video address, accused Putin of prolonging the war, saying that when the Russian leader speaks to Trump, he will have been aware of the ceasefire proposal for a week.

"This proposal could have been implemented long ago," he said. "Every day in wartime means human lives," he said.

Asked what concessions were being considered in ceasefire negotiations, Trump said:

"We'll be talking about land. We'll be talking about power plants ... We're already talking about that, dividing up certain assets."

He gave no details, but appeared to be referring to the Russian-occupied Zaporizhzhia facility in Ukraine, Europe's largest nuclear plant. Russia and Ukraine have accused each other of risking an accident at the plant with their actions.

White House press secretary Karoline Leavitt told a regular briefing on Monday that Trump and Putin would discuss a power plant "on the border" of Russia and Ukraine. Kremlin spokesperson Dmitry Peskov declined to comment on Trump's remarks about land and power plants.

The Kremlin said last week that Putin had sent Trump a message about his ceasefire plan via US envoy Steve Witkoff, who held talks in Moscow, expressing "cautious optimism" that a deal could be reached to end the three-year conflict.

Trump to discuss power plant with Russia's Putin, White House says. – Reuters

In separate appearances on TV shows in the United States, Witkoff, Secretary of State Marco Rubio, and Trump's National Security Adviser, Mike Waltz, emphasised there were still challenges to be worked out before Russia agrees to a ceasefire, much less a final peaceful resolution to the war.

Asked on ABC whether the US would accept a peace deal in which Russia was allowed to keep Ukrainian territory that it has seized, Waltz replied: "We have to ask ourselves, is it in our national interest? Is it realistic? ... Are we going to drive every Russian off of every inch of Ukrainian soil?"

"We can talk about what is right or wrong but also have to talk about the reality of the situation on the ground," he said, adding that the alternative to finding compromises on land and other issues was "endless warfare" and even World War Three.

'Ironclad guarantees' 

Zelensky has said he sees a good chance to end the war after Kyiv accepted the US proposal for a 30-day interim ceasefire.

However, Zelensky has consistently said the sovereignty of his country is not negotiable and that Russia must surrender the territory it has seized. Russia seized the Crimean Peninsula in 2014 and now controls most of four eastern Ukrainian regions since it invaded the country in 2022.

Zelensky has not responded publicly to Waltz's remarks.

Ukrainian servicemen fire a mortar towards Russian troops at the frontline. – Reuters

Russia will seek "ironclad" guarantees in any peace deal that NATO nations exclude Kyiv from membership and that Ukraine will remain neutral, Russian Deputy Foreign Minister Alexander Grushko told Russian media outlet Izvestia in remarks that made no reference to the ceasefire proposal.

"We will demand that ironclad security guarantees become part of this agreement," Izvestia cited Grushko as saying.

Putin says his actions in Ukraine are aimed at protecting Russia's national security against what he casts as an aggressive and hostile West, in particular NATO's eastward expansion. Ukraine and its Western partners say Russia is waging an unprovoked war of aggression and an imperial-style land grab.

Moscow has demanded that Ukraine drop its NATO ambitions, that Russia keep control of all Ukrainian territory seized, and that the size of the Ukrainian army be limited. It also wants Western sanctions eased and a presidential election in Ukraine, which Kyiv says is premature while martial law is in force.

The European Union's foreign policy chief, Kaja Kallas, said that the conditions demanded by Russia to agree to a ceasefire showed that Moscow does not really want peace.

Finland's Foreign Minister Elina Valtonen said the onus should be on Russia as the invading country, not Ukraine, to make concessions "because otherwise you would be compromising international law."

Kallas: Russian conditions show Moscow does not want Ukraine peace. – Reuters

British Prime Minister Keir Starmer said that "a significant number" of nations – including Britain and France – were willing to send peacekeeping troops to Ukraine in the event of a peace deal with Russia. Defence chiefs will meet this week to firm up plans.

Russia has ruled out peacekeepers until the war has ended.

"If they appear there, it means that they are deployed in the conflict zone with all the consequences for these contingents as parties to the conflict," Russia's Grushko said.

"We can talk about unarmed observers, a civilian mission that would monitor the implementation of individual aspects of this agreement, or guarantee mechanisms. In the meantime, it's just hot air."