US will drop Russia-Ukraine deal if no progress: Rubio

US President Donald Trump will walk away from trying to broker a Russia-Ukraine peace deal within days unless there are clear signs that a deal can be done, US Secretary of State Marco Rubio says.

"We're not going to continue with this endeavour for weeks and months on end, so we need to determine very quickly now - and I'm talking about a matter of days - whether or not this is doable in the next few weeks," Rubio said in Paris on Friday after meeting European and Ukrainian leaders.

"If it's not possible, if we're so far apart that this is not going to happen, then I think the president is probably at a point where he's going to say, 'Well, we're done'."

There was no immediate comment from Paris, London, Berlin or Kyiv on Rubio's statement.

Three European diplomatic sources told Reuters that Rubio's comments reflected growing frustration in the White House over Russian intransigence to end the war.

Kremlin spokesman Dmitry Peskov said some progress on a peace settlement had already been made but contacts with Washington were difficult.

He said Russia was striving to resolve the conflict while ensuring its own interests.

Moscow remained open to dialogue with the US, he said.

Rubio's threats came amid signs of some progress in US talks with Ukraine.

Trump said he expected to sign a minerals deal with Kyiv next week after an attempt in February fell apart following Ukrainian President Volodymyr Zelenskiy's Oval Office clash with Trump and Vice-President JD Vance.

Late on Thursday, the US and Ukrainian governments signed a memorandum of intent, signalling their intent to finalise the minerals deal.

The talks in Paris on Thursday were the first substantive, high level and in-person talks on Trump's peace push that have included European powers.

Rubio said a US peace framework he presented received an "encouraging reception".

Zelenskiy's office called the talks constructive and positive.

It was unclear why Rubio's tone shifted so dramatically overnight.

Still, his comments on Friday underline mounting frustrations in the White House over a lack of progress to settle a growing list of geopolitical challenges.

Trump promised during his election campaign to end the war in Ukraine within his first 24 hours in the White House.

He moderated that claim on taking office, suggesting a deal by April or May as obstacles mounted.

He has pressured both sides to negotiate, threatening tougher sanctions on Russia or an end to US military support for Kyiv.

Both Ukraine and Russia showed up for US-brokered talks in Saudi Arabia, which resulted in a partial ceasefire, but nothing more.

Meanwhile, the war has continued, including a recent Russian missile attack that hit Sumy in northeastern Ukraine, killing 35 people - an attack Trump called a "mistake".

If Washington walks away, efforts to broker a peace would likely founder because no other nation is able to bring similar pressure on both Moscow and Kyiv.

Other impacts are unclear. The United States could keep its current policy: maintaining sanctions on Russia and keeping US aid flowing to Kyiv.

Alternatively, Trump could decide to halt payments to Ukraine.

Rubio said he spoke with Russian Foreign Minister Sergei Lavrov after the "constructive" Paris talks and briefed him on "some of the elements of" the US peace framework.

Russian President Vladimir Putin has said he wants Ukraine to drop its ambitions to join NATO, Russia to control the four Ukrainian regions it has claimed as its own, and the size of the Ukrainian army to be limited.

Kyiv says those demands are tantamount to demanding its capitulation.