WASHINGTON — International inspectors said on Monday that Iran was ramping up its production of nuclear fuel, following through on a threat to begin walking away from restrictions agreed to in a 2015 nuclear accord that President Trump has abandoned.
The announcement of Iran’s actions came from Yukiya Amano, the director general of the International Atomic Energy Agency, which is responsible for verifying Iran’s compliance with its obligations under the 2015 deal negotiated by the Obama administration.
“Yes, production rate is increasing,’’ he said at a news conference in Vienna, in response to a question about whether Iran was enforcing orders President Hassan Rouhani issued last month. The fuel in question is low-enriched uranium, used in nuclear power plants. It would have to be further enriched to be used in a weapon.
Mr. Amano, clearly seeking to avoid further inflaming tensions between the United States and Iran, did not say how much Tehran had stepped up production — or when it might reach the limit of how much nuclear material it is allowed to retain under the 2015 agreement.
Nonetheless, his announcement added to the sense that the two sides were engaged in a game of nuclear chicken — with the United States imposing new sanctions on Iran while demanding that Iran remain in compliance with the accord despite Mr. Trump’s disavowal of it.
“I am worried about increasing tensions over the Iranian nuclear issue,’’ Mr. Amano, a former Japanese diplomat, said during a speech to the agency’s board of governors. “It is essential that Iran fully implements its nuclear-related commitments” under the accord, he said.
American sanctions may actually speed the moment at which Iran is in violation of the agreement’s terms. In May, the State Department announced that it might penalize any country that transfers any enriched uranium out of Iranian territory. Until now, Iran has shipped most of the low-enriched uranium it produces out of the country, swapping it for natural uranium. That allows it to continue producing token amounts of nuclear fuel for power plants without building up a stockpile that might later be used in a weapons program.
By declaring on May 3 that swapping out Iran’s fuel “could be sanctionable’’ activity, the State Department was essentially creating conditions that will, over time, force Iran to violate the nuclear stockpile limits negotiated during the Obama administration by John Kerry, the former secretary of state. And by producing uranium faster than it has in years, Iran is essentially speeding toward that day. Taken together, that combination could easily create a crisis of the kind that brought the United States, Iran and Israel to the brink of military conflict many times before the negotiation of the nuclear deal.
In an interview several weeks ago, Secretary of State Mike Pompeo, who has driven much of the administration’s Iran policy, warned that Tehran would not be allowed to amass enough nuclear material that would permit it to “break out” and produce a weapon in less than one year — the same threshold the Obama administration set.
But Mr. Pompeo did not say how Washington might react if Iran’s inventory of nuclear material increased to the point that Iran got within striking distance of building a bomb.
Mr. Rouhani, meanwhile, is gradually raising the temperature, testing whether he can peel European governments away from the United States in the conflict over the 2015 accord. In his speech in May, he set a series of 60-day deadlines, threatening to discard nuclear restrictions, one by one, if Britain, France and Germany did not break the sanctions that the United States has imposed unilaterally. The first step, Mr. Rouhani said, would be a quadrupling of uranium production.
The second step, come July, he said, would be increasing the level of enrichment, taking the country closer to bomb-grade uranium. But Mr. Rouhani did not say how much the enrichment level would increase.
Mr. Amano’s statement on Monday came as Germany’s foreign minister, Heiko Maas, was visiting Iran, trying to succeed in the delicate work of separating Germany from American policy while not threatening Germany’s alliance with the United States.
“The situation in the region here is highly explosive and extremely serious,’’ he said. “A dangerous escalation of existing tensions can also lead to a military escalation.”
But as Iran walks back from its nuclear commitments, American diplomats say, it will be increasingly difficult for Germany and other Western European nations to do business with Tehran. For more than a year, Europe and Iran have discussed creating what essentially amounts to a barter system, one that would allow Europe to obtain Iranian oil in return for European goods without conducting transactions in dollars, which Washington has blocked.
Iran’s foreign minister, Mohammad Javad Zarif, has complained for months that the system has not been put into place, and in private Europeans say they have doubts it ever will be.
“We want to fulfill our obligations” under the 2015 agreement, Mr. Maas said during a joint news conference with Mr. Zarif. But he said that “we cannot work miracles.”