Washington will study ceasefire roadmaps presented by Moscow and Kiev, the head of the State Department said

The US does not want negotiations between Russia and Ukraine to drag on indefinitely, Secretary of State Marco Rubio has said, emphasizing that Washington expects concrete results.

He made the remarks after Russia and Ukraine held their first direct talks in three years in Istanbul on Friday. The countries agreed on a prisoner swap involving 1,000 people on each side, and to continue contacts once both parties have prepared detailed ceasefire proposals.

"On the one hand, we're trying to achieve peace and end a very bloody, costly, and destructive war. So there's some element of patience that is required," Rubio said in an interview aired Sunday on CBS News' Face the Nation with Margaret Brennan.

"On the other hand, we don't have time to waste. There are a lot of other things happening in the world that we also need to be paying attention to. So we don't want to be involved in this process of just endless talks. There has to be some progress, some movement forward," he added.

Rubio said the US would examine ceasefire proposals from both Russia and Ukraine. "If those papers have ideas on them that are realistic and rational, then I think we know we've made progress," he said.

The diplomat confirmed that the US is ready to impose further sanctions on Russia if no deal is reached. He expressed confidence that both chambers of Congress would pass Senator Lindsey Graham's bill introducing 500% tariffs on imports from countries that purchase Russian oil, natural gas, and uranium.

According to the White House, Rubio spoke with Russian Foreign Minister Sergey Lavrov by phone on Saturday, reiterating President Donald Trump's call for an immediate ceasefire.

Moscow has rejected demands for an unconditional 30-day ceasefire, insisting that talks must address the "root causes" of the conflict, including Ukraine's aspirations to join NATO - a move Russia considers a threat to its national security.

President Vladimir Putin has maintained that a lasting truce would require Ukraine to halt its mobilization, stop receiving weapons from abroad, and withdraw troops from Russian territory. He also warned that Kiev would likely use a temporary ceasefire to rearm and regroup.