Last year, Donald Trump promised he would end the Ukraine War in "24 hours".

Last week, he said that it would not be resolved until he and Russian President Vladimir Putin could "get together" and hash it out in person.

On Monday, the ground shifted again.

After a two-hour phone call with Putin, he said that the conditions of a peace deal could only be negotiated between Russia and Ukraine – and maybe with the help of the Pope.

Still, the US president has not lost his sense of optimism about the prospect for peace, posting on social media that the combatants would "immediately start" negotiations for a ceasefire and an end to the war.

That sentiment was somewhat at odds with the Russian view. Putin only said that his country is ready to work with Ukraine to craft a "memorandum on a possible future peace agreement".

Talks about memorandums and a "possible future" of peace hardly seem the kind of solid ground on which lasting deals can be quickly built.

Putin again emphasised that any resolution would have to address the "root causes" of the war, which Russia has claimed in past to be Ukraine's desire for closer ties to Europe.

There is a possibility that Trump's latest take on the war in Ukraine could be a sign that the US will ultimately abandon the negotiating table.

"Big egos involved, but I think something's going to happen," Trump said on Monday afternoon. "And if it doesn't, I'll just back away and they'll have to keep going."

Such a move, however, comes with its own set of questions – and risks.

If the US washes its hands of the war, as Vice-President JD Vance and Secretary of State Marco Rubio have also threatened, does it mean the US would also end any military and intelligence support for Ukraine?

And if that is the case, then it may be a development that Russia, with its greater resources compared to a Ukraine cut off from American backing, would welcome.

That prospect is enough to have Ukrainian President Volodymyr Zelensky concerned.

"It's crucial for all of us that the United States does not distance itself from the talks and the pursuit of peace," he said on Monday after the Trump-Putin call.

Putting aside Monday's rhetoric, it appears that Ukraine and Russia are set to continue some kind of talks – and talking in any form is progress after nearly three years of war.

Still to be determined is whether the Russian team will be more than the low-level delegation that travelled to Istanbul to meet with the Ukrainians last Friday.

Trump is holding out the promise of reduced sanctions on Russia – and new trade deals and economic investment – as the enticement that will move Putin toward a peace agreement.

He mentioned that again in his post-call comments. Not discussed, on the other hand, were any negative consequences, such as new sanctions on Russian banking and energy exports.

The US president last month warned that he would not tolerate Putin "tapping me along" and said that Russia should not target civilian areas.

But yesterday, Russia launched its largest drone strike of the war on Ukrainian cities, and Monday's call between the two world leaders makes clear that any ceasefire or peace deal still seems well over the horizon.