During his campaign, President Trump promised to end the Russia-Ukraine war on his first day in office. Almost 100 days later, there's still no resolution.

White House Special Envoy Steve Witkoff was in Moscow Friday for a meeting with Russian President Vladimir Putin, amid new urgency in the effort to broker peace in Ukraine.

This week, Russia launched a series of deadly bombings on Kyiv and the surrounding areas.

At least 20 Ukrainians were killed and upwards of 100 wounded in the attacks, according to local officials.

The incident prompted a rare rebuke from President Trump.

"Vladimir, stop!" the president wrote on his Truth Social platform Thursday.

Those comments came just one day after President Trump shared more criticisms of Ukraininan President Volodymyr Zelenskyy, suggesting the Ukrainian leader's refusal to cede territory to Russia "Will do nothing but prolong the "Killing field."

"I thought it would be easier to deal with Zelenskyy, so far it's been harder," President Trump said.

In new comments to Time Magazine published Friday, President Trump said "Crimea will stay with Russia."

Ukrainan officials say a plan reportedly proposed by the U.S. to officially recognize Russian control of Crimea is unacceptable.

The proposed plan also reportedly freezes current battle lines, effectively giving Russia control of about 20 percent of Ukrainian territory.

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Earlier this week, Vice President JD Vance suggested the White House could end talks if an agreement isn't reached soon.

"We've issued a very explicit proposal to both the Russians and Ukrainians, and it's time for them to either say yes or for the us to walk away from this process," Vance said.

In a recent interview, President Trump projected optimism about the prospects of reaching a deal soon — though Ukrainian officials have expressed serious concerns about the terms laid out by the U.S.