“We have to agree, that deal is dead,” said Valerie Lincy, senior associate at the Wisconsin Project on Nuclear Arms Control.

Image President Mahmoud Ahmadinejad of Iran ordered the nation’s atomic energy agency on Sunday to begin producing a special form of uranium. Credit... Atta Kenare/Agence France-Presse — Getty Images

There is every reason to believe that Mr. Ahmadinejad’s order on Sunday may represent nuclear gamesmanship. To enrich its current stockpile of uranium to roughly 20 percent purity  what is needed for the Tehran reactor, which the United States provided to the country before the Islamic Revolution  would require retooling the configuration of the nation’s centrifuges. It comes at a moment when Western intelligence agencies say that Iran has run into technical difficulties at its nuclear plants.

It is unclear if those troubles have been caused by Iran’s own technical failings, outside sabotage or some other reason. But in recent months, United States intelligence officials have told Congress and close allies, in classified briefings, that covert efforts to interfere with Iran’s capability are extremely active.

Even if Iran could produce the 20 percent enriched uranium, it would then have to manufacture it into specialized fuel rods for the reactor. That technology is most advanced in France and Argentina. Creating the capability in Iran could take years.

The announcement by Mr. Ahmadinejad comes at a time of intense diplomatic maneuvering over how to deal with Iran’s nuclear program. The United States has been working hard to persuade other nations to accept new and punishing sanctions, while Iran is trying to thwart those efforts. Iran has largely succeeded with China, which receives about 15 percent of its oil from Iran.

Until now, Iran has never enriched significant quantities of fuel beyond the level needed in ordinary nuclear reactors, part of its argument that its program is for peaceful purposes. But any effort to produce 20 percent enriched uranium would put the country in a position to produce highly enriched uranium  at the 90 percent level used for weapons  in a comparatively short time, nuclear experts say.

Mr. Ahmadinejad’s announcement that Iran would produce medical-reactor fuel itself came at a laser technology conference in Tehran, where he told Ali Akbar Salehi, head of the atomic energy agency, who was seated in the audience, to move ahead.