() Vice President JD Vance on Wednesday warned Russia and Ukraine should reach an agreement to end fighting soon, or the United States will “walk away” from peace talks.

“We’ve issued a very explicit proposal to both the Russians and the Ukrainians,” Vance told reporters. “And it’s time for them to either say yes or for the United States to walk away from this process.”

Vance’s comments, made during his four-day trip to India, came as envoys met in the United Kingdom to discuss a ceasefire in the war in Ukraine.

Vance said he feels “pretty optimistic” the European countries will “ultimately be able to get this thing over the finish line.”

“It’s now time, I think, to take, if not the final step, one of the final steps, which is, at a broad level, the parties saying, ‘We’re going to stop the killing, we’re going to freeze the territorial lines at some level close to where they are today,'” Vance said.

Last week, President Donald Trump said the negotiations were “coming to a head” and floated the idea of abandoning the talks altogether.

“Now, if for some reason, one of the two parties makes it very difficult, we’re just going to say you’re foolish. You are fools, you horrible people,” Trump said. “And we’re going to just take a pass. But hopefully, we won’t have to do that.”

When pressed on the specifics of territorial lines Wednesday, Vance told reporters that both countries will need to make concessions to reach an agreement.

“What I said is the current line somewhere close to them is where you’re ultimately, I think, going to draw the new lines in the conflict,” Vance said. “Now, of course, that means the Ukrainians and the Russians are both going to have to give up some of the territory they currently own.”

Vance’s comments came a day after Ukrainian President Volodymyr Zelenskyy said he would not cede territory to Russia in any peace agreement.

During similar talks last week in Paris, U.S. officials presented a proposal that included allowing Russia to keep control of occupied Ukrainian territory, according to a European official familiar with the matter.

Zelenskyy pushed back against the proposal during an appearance in Kyiv, saying: “There is nothing to talk about it is our land, the land of the Ukrainian people.”

The Associated Press contributed to this report.