US Secretary of State Marco Rubio said on Sunday that a peace deal between Russia and Ukraine needs to happen soon and that Washington is trying to determine whether it is worth continuing to serve as mediator.
"We cannot continue to dedicate time and resources to this effort if it's not going to come to fruition," Mr Rubio told NBC's Meet the Press.
"The last week has really been about figuring out how close are these sides really, and are they close enough that this merits a continued investment of our time as a mediator."
Special envoy Steve Witkoff visited Moscow on Saturday to discuss Washington's proposal to end the war. Mr Witkoff said the two sides were "very close to a deal".
But Mr Rubio did not say how long the Trump administration is willing to wait for a breakthrough.
He explained that the next week of talks would help determine whether the US sees a way forward.
"This week is a really critical week in which we have to make a determination about whether this is an endeavour that we want to continue to be involved in," he said.
His remarks come after US President Donald Trump held a meeting with his Ukrainian counterpart Volodymyr Zelenskyy on the sidelines of Pope Francis's funeral in Rome this weekend.
An aide to Mr Zelenskyy described the meeting as “constructive” and the White House called it “a very productive discussion”. Mr Zelenskyy said in a post on X that he was "hoping for results" from the meeting.
Critics of Mr Trump's approach to the conflict have accused him of cosying up to Russian President Vladimir Putin and freezing out Ukraine. In an interview with Time, Mr Trump said that “Crimea will stay with Russia”, referring to a territory Moscow's forces have occupied since 2014.
But Mr Trump lashed out at Mr Putin in recent days over deadly attacks on Ukraine, and on Saturday he cast new doubts on how serious Russia was about ending the conflict.
“There was no reason for Putin to be shooting missiles into civilian areas, cities and towns over the last few days,” Mr Trump said in a post on his Truth Social platform.
“It makes me think that maybe he doesn't want to stop the war, he's just tapping me along, and has to be dealt with differently, through 'banking' or 'secondary sanctions?' Too many people are dying.”
Mr Rubio echoed this desire to focus on peace talks over sanctions.
"The minute you start doing that kind of stuff [issuing sanctions], you're walking away from it [peace talks] – you've now doomed yourself to another two years of war, and we don't want to see it happen," he said.
