Ukrainian President Volodymyr Zelenskyy has told his aides to reject Trump administration officials’ proposal that would grant the United States significant access to Ukraine’s rare earth minerals, a Ukrainian official close to Zelenskyy confirmed to NBC News.

U.S. officials said the proposal would be a form of repayment for the support Washington has provided Kyiv since its war with Russia began, but according to the aide close to him, Zelenskyy did not feel the agreement included adequate security guarantees for Ukraine.

Treasury Secretary Scott Bessent first proposed the draft agreement, which would have granted the United States 50% ownership of Ukraine’s rare earth minerals, to Zelenskyy last week, NBC News reported. 

“I didn’t let the ministers sign a relevant agreement because in my view it is not ready to protect us, our interest,” Zelenskyy said at the Munich Security Conference in a quote first reported by The Associated Press on Saturday.

A U.S. official called Zelenskyy’s response to the offer “short-sighted,” adding that it would secure an “enduring partnership” between the two countries.

“Binding economic ties with the United States will be the best guarantee against future aggression and an integral part of lasting peace. The U.S. recognizes this, the Russians recognize this, and the Ukrainians must recognize this,” the official said.

U.S. officials briefed on the proposal signaled an openness to deploying American troops to Ukraine to guard the minerals — but only after a deal with Russia to end the war was agreed to.

Zelenskyy declined to sign the draft when Bessent first presented it during their meeting in Kyiv on Wednesday, saying he needed to study it and consult others about it, officials briefed on the meeting told NBC News.

President Donald Trump said in a recent interview with Fox News that he wanted the United States to get $500 billion worth of Ukraine’s rare earth minerals and that Kyiv “essentially agreed to do so.”

Ukraine has some of the world’s largest reserves of titanium and iron ore, both of which are used to make a variety of technology products. Many of the minerals, however, are in areas now controlled by Russian troops, according to U.S. officials.

Ukrainian officials have said Zelenskyy has long backed the idea of exchanging “critical resources” for continued U.S. support, calling the idea part of the “Victory Plan” that he presented to Trump at a meeting last fall.

In an exclusive interview Friday at the Munich Security Conference, Zelenskyy told NBC News’ “Meet the Press” moderator Kristen Welker that Ukraine would have a “low chance to survive without support of the United States,” but Trump has long questioned the amount of support the U.S. has sent to it, referring to Zelenskyy at a campaign event last year as “the greatest salesman of all time.”