WASHINGTON — The United States presented its first formal proposal to Iran for elements of a nuclear deal Saturday, just hours after U.N. inspectors reported a major surge over the past three months in the size of Tehran’s stockpile of near-bomb-grade uranium.

The document was described by officials familiar with the diplomatic exchanges as a series of bullet points but not a full draft of an agreement.

It calls for Iran to cease all enrichment of uranium and proposes the creation of a regional consortium to produce nuclear power that would involve Iran, Saudi Arabia and other Arab states, and the United States. The offer marked the first time since negotiations began in early April that the lead U.S. negotiator, Steve Witkoff, had put forth a proposal on paper.

The delivery of the document was made public in a social media post by Abbas Araghchi, Iran’s foreign minister, who said it had been delivered by his counterpart from Oman, which has been hosting the talks. The White House later confirmed the action.

“President (Donald) Trump has made it clear that Iran can never obtain a nuclear bomb,” Karoline Leavitt, the White House press secretary, said in a statement. “Special envoy Witkoff has sent a detailed and acceptable proposal to the Iranian regime, and it’s in their best interest to accept it. Out of respect for the ongoing deal, the administration will not comment on details of the proposal to the media.”

Many experts are skeptical that Iran’s aging supreme leader, Ayatollah Ali Khamenei, will approve a deal that would essentially shut down the vast nuclear production facilities that the Iranians have spent billions to construct, and that have been the targets of sabotage by the United States and Israel.

Araghchi said Iran would “respond to the U.S. proposal in line with the principles, national interests and rights of the people of Iran.” In recent weeks, Iranian officials have rejected U.S. demands to terminate all nuclear enrichment, declaring they would never give up their right to produce nuclear fuel. That capability gives Iran the status of a threshold nuclear state, one that could rapidly build a weapon if it decided to.

The revelation of Iran’s production surge of uranium enriched to 60%, just below bomb-grade, was a vivid illustration of its effort to gain leverage in the negotiation. The increase gives Tehran the capability to produce the fuel for roughly 10 weapons, up from around five or six when President Donald Trump was inaugurated in January.

A pair of reports by the International Atomic Energy Agency, obtained by The New York Times, portray an Iranian regime that has decided to surge ahead with its production, presumably to gain leverage in the negotiations with Witkoff, who is the administration’s envoy for the Middle East.

The director-general of the IAEA, Rafael Grossi, said the report on Iran’s production surge indicated that “we need to get to a diplomatic resolution, under a very robust IAEA inspection system.”