KYIV, Ukraine — Ukrainian President Volodymyr Zelenskyy said Sunday that he is willing to step down if it meant peace in Ukraine, which on Monday marks three years since Russia invaded. His remark came days after President Donald Trump questioned his legitimacy and called him a “dictator without elections,” echoing a Kremlin talking point.

At the same time, Zelenskyy continued to push back against Trump’s insistence that he sign a minerals deal that Ukraine says is unpalatable. And he announced a meeting Monday of more than 30 countries in person or online as a kind of coalition of support for Ukraine’s war effort.

It was not immediately clear whether Zelenskyy had seriously considered the option of stepping down or was merely responding to the latest jabs from Washington and Moscow. He said he could trade his departure for Ukraine’s entry into NATO — a highly unlikely scenario, given Trump’s opposition to allowing Ukraine into the military alliance.

“If peace for Ukraine requires me to step down, I’m ready,” Zelenskyy said during a news conference Sunday, the eve of the third anniversary of Russia’s invasion. “Another scenario — I could trade my position for NATO membership, if that’s what it takes.”

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 is 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.

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

“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 the war-torn country. “We’re asking for rare earth and oil — anything we can get.”

Frustration over the drawn-out negotiations has fueled an escalating dispute between Zelenskyy and Trump. The American leader questioned Zelenskyy’s political legitimacy and suggested that Ukraine had started the war with Russia. The Ukrainian leader said Trump is living in a “web of disinformation.”

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. Two Ukrainian officials, speaking on the condition of anonymity to discuss the negotiations, said Ukraine sent back amendments Saturday night.

The new draft agreement reiterated a U.S. demand that Ukraine relinquish half of its revenues from the extraction of natural resources — including minerals, gas and oil — as well as earnings from ports and other infrastructure.

Under the proposed deal, 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 is disproportionate with the value of U.S. aid to Ukraine so far — about $120 billion, according to the Kiel Institute, a German think tank — and he is not ready to “acknowledge” that Ukraine owes 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.

“The agreement states that for every dollar of aid, Ukraine must return $2,” Zelenskyy said Sunday. “Simply put, it’s a 100% loan. I have to repay the principal plus another 100% on top.”

The agreement does not commit the United States to security guarantees for Ukraine or promise further military support for the country. The word “security” was even deleted from a formulation contained in a previous version of the deal, dated Feb. 14 and reviewed by the Times, which stated that both countries aimed to achieve “lasting peace and security in Ukraine.”

The White House has argued that the mere presence of U.S. economic interests in Ukraine will deter future Russian aggression.

But Zelenskyy pointed out that the presence of U.S. companies in eastern Ukraine before the war had not deterred Russia from attacking and occupying those territories.

“Clearly, this isn’t a 100% guarantee that Russians won’t go where they’ve already been,” he said Sunday.

While Ukraine continues to negotiate the minerals deal, Moscow shows no signs of easing its attacks, with Russia launching a huge drone assault on Ukrainian cities overnight.

In a statement that couldn’t be confirmed, the Ukrainian air force said Russia had launched 267 drones, calling it a record since the war began three years ago.