Iran’s foreign minister rejected on Thursday any new negotiation with the United States over extending the length or conditions of the 2015 nuclear accord, saying that Iran would talk about changing the accord only if every concession it made — including giving up nuclear fuel — were reconsidered.

In an interview, the foreign minister, Mohammad Javad Zarif, said that would mean Iran would retake possession of the stockpile of nuclear fuel it shipped to Russia when the accord took effect.

“Are you prepared to return to us 10 tons of enriched uranium?,” Mr. Zarif said of the relinquished stockpile — one of Iran’s biggest concessions — about 98 percent of the country’s nuclear fuel holdings.

Under the agreement, Iran retains an amount of enriched uranium too small to make a single atomic weapon.

Mr. Zarif, who was educated in the United States, spoke with reporters, columnists and editorial writers for The New York Times, a day after he conferred privately with counterparts from the six countries that negotiated the deal with Iran — Britain, China, France, Germany, Russia and the United States — on the sidelines of the United Nations General Assembly meetings in New York.

It was the first time Mr. Zarif had met with Secretary of State Rex W. Tillerson, who has said the United States wants to “revisit” what he described as flaws in the accord even as he acknowledged Iran is abiding by its terms.

Mr. Zarif, who negotiated details of the Iran accord with then-Secretary of State John Kerry, dismissed the Trump administration as “seriously ill-informed” about the limits on Iran contained in the deal.

He described President Trump’s speech to the United Nations on Tuesday, in which Mr. Trump called the nuclear accord a one-sided embarrassment to the United States that he may abandon, as “absurd.”

What the administration really wanted, Mr. Zarif said, was to keep the Iranian concessions while trying to extract more from Iran — but with no new concessions from the United States or other parties. That kind of position, he said, contradicted the premise of any negotiated deal.

“By definition, a deal is not perfect, because in any deal you have to give and take,” he said. “Otherwise you won’t have a deal.”

He further dismissed the idea of an addendum to the agreement to address the Trump administration’s objections, an idea that American officials say has been floated within the administration as a possible diplomatic way forward.

“Why should we discuss an addendum?,” Mr. Zarif said. “If you want to have an addendum, there has to be an addendum on everything.”

Mr. Trump has strongly hinted he is prepared to “decertify” Iran’s compliance with the deal, even while Mr. Tillerson, speaking to reporters after his encounter with Mr. Zarif on Wednesday evening, acknowledged that Iran is in “technical compliance.” Continue reading.