KYIV, Ukraine >> President Volodymyr Zelenskyy pushed back Sunday against demands from the Trump administration for billions in Ukrainian natural resources and for holding peace talks that exclude Ukraine, while announcing plans for a major summit of European leaders Monday.

The Ukrainian leader’s efforts to shore up European support while pressing ahead on negotiations with the United States came despite ominous messages from President Donald Trump in recent days belittling Zelenskyy and issuing threats if Ukraine does not soon agree to a minerals deal.

Zelenskyy suggested that in assailing Ukraine, Trump had chosen the wrong adversary.

“Peace through force, but toward Russia, not in the other direction,” Zelenskyy said of how he would like to see U.S. efforts to end the war.

Zelenskyy, speaking at a news conference in Kyiv, said that he was willing to step down if it meant peace in Ukraine. His remark came days after Trump questioned his legitimacy and called him a “dictator without elections,” echoing a Kremlin talking point.

It was not immediately clear whether Zelenskyy is seriously considering the option of stepping down or was merely responding to the latest jabs from Washington and Moscow. He added that he would trade his departure for Ukraine’s entry into NATO — perhaps a tongue-in-cheek offer, since both Trump and President Vladimir Putin of Russia solidly oppose Ukraine’s joining the military alliance.

“If peace for Ukraine requires me to step down, I’m ready,” Zelenskyy said on the eve of the third anniversary of Russia’s full-scale invasion. “Another scenario: I could trade my position for NATO membership, if that’s what it takes,” he added.

The Ukrainian leader said that more than 30 countries would participate in meetings Monday, either in person in Kyiv or virtually, as a kind of coalition of support for Ukraine’s war effort. The gathering, he said, will focus on military aid and security guarantees to enforce any potential ceasefire.

Zelenskyy has said he will not accept any agreement negotiated between the United States and Russia without Ukraine’s participation.

“This is how we see this negotiation table: Ukraine as part of Europe, Europe, the United States and Russia. That’s approximately how we envision it,” he said.

Frustration over the drawn-out negotiations has fueled an escalating dispute between Zelenskyy and Trump, especially after the American leader questioned Zelenskyy’s political legitimacy and falsely claimed that Ukraine had started the war with Russia.

Zelenskyy has been advised by European allies to tone down his confrontation with the American president. But on Sunday, he did not back away from his earlier comments and repeated his assertion that Trump is living in a disinformation bubble.

Zelenskyy’s pushback Sunday could further anger Trump, who is pressing for a minerals deal and a peace agreement on terms he wants to dictate.

For now, Zelenskyy said, Ukraine and the United States remain locked in negotiations over a deal to trade Ukraine’s minerals and other natural resources for U.S. aid. Zelenskyy said he was still not ready to sign the United States’ latest proposal, which would require Ukraine to pay the United States $500 billion using revenues from its natural resources.

“I am not signing something that 10 generations of Ukrainians will have to repay,” Zelenskyy said, noting that negotiations would continue. Drawing on Ukraine’s revenue from natural resources, he said, it might take 250 years to pay $500 billion, which he called an unrealistic sum.

At the same time, Zelenskyy said he may ultimately have little choice but to sign the deal. “If we are forced and we cannot do without it, then we should probably go for it,” he said.

On Saturday evening, Trump ramped up pressure on Ukraine to sign the minerals deal, which has now been under negotiation for more than 10 days. Several draft agreements have already been rejected by the Ukrainian side because they did not contain specific U.S. security guarantees that would protect the country against further Russian aggression.

“I think we’re pretty close to a deal, and we better be close to a deal,” Trump told the Conservative Political Action Conference on Saturday evening, noting that he wanted payback for past U.S. military and financial assistance to Ukraine. He also said, “We’re asking for rare earth and oil — anything we can get.”

On Friday, the United States proposed a new draft agreement, obtained by The New York Times, which still lacked security guarantees for Ukraine and included even tougher financial terms. The new draft reiterated a U.S. demand that Ukraine relinquish half of its revenues from natural resource extraction, including minerals, gas and oil, as well as earnings from ports and other infrastructure.

Under the proposed terms, those revenues would be directed to a fund in which the United States would hold 100% financial interest, and Ukraine should contribute to the fund until it reaches $500 billion. That sum is more than twice the value of Ukraine’s economic output in 2021, before the war.

Zelenskyy said the sum was disproportionate with the value of U.S. aid to Ukraine so far — about $120 billion, according to the Kiel Institute, a German research institute — and he would not “acknowledge” that Ukraine owed the U.S. $500 billion, “no matter what anyone says.”

Zelenskyy also highlighted another sticking point in the proposed deal: that Ukraine would be required to repay the United States twice the value of future U.S. aid.