Amid signs that Iran's military is resisting efforts to open up its nuclear program to deeper inspection, President Barack Obama's administration imposed sanctions Friday on several Iranian organizations, including one run by the scientist who is widely believed to direct research on building nuclear weapons.
In a statement, the White House said the sanctions were a continuation of its strategy to crack down on groups suspected of seeking to avoid or violate existing sanctions, even as "the United States remains committed" to reaching an accord by late November that includes "a long-term, comprehensive solution that provides confidence that Iran's nuclear program is exclusively peaceful."
But in the month and a half since the talks were extended, Iran has missed a major deadline to provide information about its nuclear research, declared it would not allow visits to a military site suspected of being part of nuclear component testing and said it was completing work on far more powerful centrifuges to make nuclear fuel.
The most notable of the new penalties was against the Organization of Defensive Innovation and Research, created 3½ years ago by Mohsen Fakhrizadeh, who is considered the father of Iran's on-again, off-again nuclear weapons research efforts in the 1990s and through the last decade.
He left Malek-Ashtar University of Technology in 2011 to create the new organization, one of several reconfigurations of the Iranian nuclear infrastructure that U.S. and European intelligence agencies believe are part of an effort to hide the size and scope of Iran's efforts.
Fakhrizadeh, a former professor, has long been on United Nations lists of officials subject to sanctions.
The U.S. announcement comes just days after Iran said it would not allow inspectors in Parchin, a site they last visited years ago, and which has been extensively cleansed in recent years, according to satellite photographs that show extensive earth-moving efforts around suspected test sites.
A Monday deadline for turning over data to the International Atomic Energy Agency passed without the transfer of the information although Iran has said it is working on answering many of the inspectors' questions.
Iran has also declared that it is speeding ahead with the manufacture of a new generation of centrifuges that could enrich uranium up to 24 times faster than those now installed at the country's two main enrichment sites.
"Manufacturing and production of new centrifuges is our right," the head of Iran's atomic energy agency, Ali Akbar Salehi, told Iranian news organizations this week.
But the Iranian reports indicated that only "mechanical" testing of the new centrifuges had been conducted. It is not clear whether that would constitute a violation of the agreement it signed last year to freeze nuclear activity. There is no evidence that the new centrifuges have been fed with nuclear fuel.
Salehi, in separate comments, also indicated that Iran is redesigning its nuclear reactor near the town of Arak so that it will produce less plutonium -- a change that could slow the inauguration of the new reactor by up to three years, he said.
The State Department sanctions were also aimed at the Arak reactor. It designated Iran's Nuclear Science and Technology Research Institute, which it said was helping build the reactor that, "as presently designed, would provide Iran the capability to produce plutonium from the reactor's spent fuel that could be used in nuclear weapons."
For the first time, the administration said in public that Iran was at work on a process that seemed aimed at allowing the country to reprocess plutonium, much as North Korea has, to fabricate weapons fuel. But there is no evidence that any of that reprocessing has taken place, and Iran so far is not known to have produced any plutonium.
Also Friday, the chief of Iran's Revolutionary Guard navy confirmed that a U.S. Coast Guard vessel fired on an Iranian fishing boat in the Persian Gulf this week but he insisted the episode was not a "clash."
The U.S. Navy's Bahrain-based 5th Fleet said personnel on a small boat dispatched from the U.S. Coast Guard patrol boat Monomoy fired a single shot Tuesday when they saw the crew on a nearby Iranian dhow training a .50-caliber machine gun on them and preparing to fire.
No one was hurt in the encounter.
The shot from the U.S. patrol boat was fired "in the air about 3 miles away" from the Iranian boat, Adm. Ali Fadavi of Iran's Revolutionary Guard was quoted as saying by the Tasnim News Agency.
"It wasn't a clash but a single shot in the air ... there was no clash between Iranian and American forces," Fadavi said, adding that "Americans feared and felt danger from a fishing dhow."
Fadavi, the Iranian officer, also said the Americans "should be fearful" as long as they are in the Persian Gulf. Tehran has long decried the U.S. presence in the critical waterway as a source of tension in the region.
Information for this article was contributed by David E. Sanger of The New York Times and by Nasser Karimi of The Associated Press.
A Section on 08/30/2014