Iran’s atomic energy agency said Saturday that it was breaking out of another set of limits on its nuclear research and production that were imposed under the deal it struck with the Obama administration and that President Trump renounced last year.
But the details suggested that Iran was more interested in increasing pressure on European nations to find a way around American-imposed sanctions than in carrying out a full-scale effort to restore the capabilities it gave up in a 2015 agreement with the West.
During a news conference shown live on Iranian television, a spokesman for the agency, Behrouz Kamalvandi, confirmed that Iran had begun steps to conduct work on advanced centrifuges — the equipment that spins at supersonic speed to purify uranium, a fuel for nuclear power and nuclear weapons — in ways that are prohibited under the 2015 deal. Mr. Trump renounced the accord more than a year ago, but until four months ago Iran was continuing to comply with all of its major restrictions.
It was the third time this year that Iran had announced steps to break from those limits, saying it would no longer abide by an agreement that the United States was violating by reimposing sanctions. The accord required all signatories to lift many sanctions on Iran while it was in compliance; the European Union, Russia and China have all continued to honor the agreement, in a split from the Trump administration.
“We have started lifting limitations on our research and development imposed by the deal,” Mr. Kamalvandi said. “It will include development of more rapid and advanced centrifuges.”
In fact, the deal did envision enabling Iran to continue research, but not to activate the centrifuges by injecting them with uranium and building up a stockpile. In previous announcements, Iran has already said it was breaching the stockpile limits, and a recent report by inspectors from the International Atomic Energy Agency confirmed that Tehran was once again accumulating fuel. But the amounts so far have been small, and well short of what Iran would need, both in quantity and enrichment level, to produce a single nuclear weapon.
The steps announced Saturday, which echoed a letter that Iran’s foreign minister, Mohammad Javad Zarif, sent to the European Union on Thursday, appeared to be intended more to give Iran negotiating leverage than to significantly further its development of a nuclear weapon.
Mr. Zarif has often said the steps Iran has taken could be undone if France and other European nations agreed to compensate the country for oil sales lost because of American sanctions. This month France presented Iran with a proposal for a $15 billion line of credit, secured by future oil shipments, that was devised to avoid American sanctions.
But later statements suggested that deal was contingent on an agreement with the United States not to penalize countries or companies involved in the extension of what amounts to a loan to Iran. The State Department’s Iran envoy, Brian H. Hook, appeared to dismiss the chances of such an agreement during a news conference with reporters. On Wednesday, the Trump administration announced additional sanctions in an effort to increase what Secretary of State Mike Pompeo has called a “maximum pressure” campaign.
The State Department had no immediate reaction to the Iranian statement. But on Friday, Mr. Pompeo wrote on Twitter, “We are confident that the UK, France and Germany — indeed, all civilized nations — will take decisive actions to stop Iran’s nuclear extortion.”
In fact, American officials are not confident at all. Since Mr. Trump left the agreement in May 2018, not a single other participant has joined him in renouncing it or reimposing sanctions. Rather, the Europeans have sought workarounds that would keep Iran within the terms of the deal, and they have argued that Mr. Trump erred gravely by scrapping the agreement rather than building on it. Russia and China appear to be looking for ways to help Iran sell oil as well.
In Saturday’s announcement, the Iranians omitted one key detail: how much they will push the level of uranium enrichment. They are still enriching now at purities of around 4.5 percent, modestly above the limit required under the 2015 accord but useful only for fueling nuclear power plants. There had been speculation that Iran would crank that up to 20 percent, a level that would be useful in a research reactor in Tehran, supplied by the United States decades ago, that produced medical isotopes.
Iranian officials have skirted that question, but Mr. Kamalvandi said the country had the right to go beyond 20 percent. “Right now there is no need for that,’’ he said, according to Iranian news reports.
The other lingering question is whether this pressure from Iran is intended to lead to a meeting between Mr. Trump and Iran’s president, Hassan Rouhani, who are both scheduled to be in New York later this month for the opening of the United Nations General Assembly.
Mr. Rouhani has never met an American president, though he spoke with President Barack Obama by phone, and Mr. Trump has said he would be open to a discussion without preconditions. But several administration officials said in recent days they believed the political risk for Mr. Rouhani would be too high, especially after the United States’ recent efforts to escalate sanctions, including against Mr. Zarif, the foreign minister, who would presumably be at the center of any negotiations.