President Volodymyr Zelensky said on Thursday that Ukraine will work “swiftly and very sensibly” on an agreement granting the United States access to its natural resources, in an apparent overture to tamp down tensions that had flared with President Trump over the deal.

Kyiv has focused on strengthening its negotiating position as the United States and Russia open talks on ending the war — with or without Ukraine’s involvement. In a flurry of diplomacy on Thursday and Friday, Mr. Zelensky spoke with half a dozen leaders in Europe and Canada to shore up other sources of support.

As he did so, however, Mr. Trump said in a radio interview on Friday that the Ukrainian president did not need to participate in talks intended to end the conflict on his soil.

“I don’t think he’s very important to be at meetings to be honest with you, he’s been there for three years,” Mr. Trump told Brian Kilmeade, the Fox News host, adding that he had been watching Mr. Zelensky “negotiate with no cards.”

“And you get sick of it,” Trump said. “You just get sick of it. And I’ve had it.”

Kyiv and Moscow engaged in direct talks early in the invasion but since April of 2022 have negotiated only over prisoner of war exchanges and to return Ukrainian children from Russia.

The idea of trading natural resources for U.S. assistance was first put forward by Ukraine, but Mr. Zelensky balked when the U.S. proposal suggested that Kyiv provide access to profits from 50 percent of the country’s minerals and energy resources. Mr. Zelensky had also objected that the deal included no American security commitments.