Meanwhile, the UN nuclear watchdog said Iran now plans to enrich uranium with a second set of advanced centrifuges at its Fordo underground facility amid opposition.
A Cyclone USS Sirocco patrol boat and a Spearhead USNS Choctaw County fast expedition vehicle were in a close encounter with three Iranian speedboats as they crossed the Strait of Hormuz to enter the Persian Gulf, the Navy said.
A video released by the Bahrain-based 5th Navy Fleet shows high-speed Guard Boghammar facing Sirocco. Siroko repeatedly inflates his horn at Bogamar, who turns as he approaches. The rocket’s shot is heard but not seen as Bogamar passes Siroko with an Iranian flag flying over it.
The Navy said Boghammar had approached 50 yards (45 meters) from Sirocco, increasing the risk of the ships colliding with each other. The overall meeting lasted about an hour, the Navy said.
“The Guardian’s actions do not meet international standards for professional or safe maritime behavior, which increases the risk of miscalculations and collisions,” the Navy said.
Iran did not immediately acknowledge the incident in the strategic waterway – a fifth of all traded oil passes through the strait.
The Navy separately told the Associated Press that this was the second so-called “unsafe and unprofessional” incident with Iran in recent months.
On March 4, three Guards ships had a tense collision for more than two hours with Navy and US Coast Guard ships as they traveled from the Persian Gulf across the Strait, the Navy said. In this incident, the guard’s catamaran Shahid Nazeri came 25 yards (22 meters) from USCGC Robert Goldman, the Navy said.
“The two U.S. Coast Guard boats issued numerous warnings via radio bridge to bridge and deployed warning flares,” the Navy said.
The Navy did not specify why it did not announce the previous incident, especially after a larger ship came even closer to a US warship. However, this was precisely when the deal in Vienna between Iran and the world powers to restore the nuclear deal seemed possible before negotiations failed.
Iran and world powers agreed in 2015 to a nuclear deal that saw Tehran drastically limit uranium enrichment in exchange for lifting economic sanctions. In 2018, then-President Donald Trump unilaterally withdrew America from the agreement, rising tensions in the wider Middle East and causing a series of attacks and incidents.
Talks in Vienna to resume the deal have been “paused” since March. After the failure of the deal, Iran used modern centrifuges and rapidly growing reserves of enriched uranium. And earlier this month, Iran has removed 27 surveillance cameras from the United Nations International Atomic Energy Agency. The head of the agency warned that this could deal a “fatal blow” to the nuclear deal.
The IAEA said on Tuesday that its inspectors had confirmed that Iran was preparing to enrich uranium through a new cascade of 166 advanced IR-6 centrifuges at its underground facility, Ford. Iran already has a cascade of IR-6s operating in Fordo, near the holy Shiite city of Qom, about 90 kilometers (55 miles) southwest of Tehran. They enrich up to 20% purity.
The IAEA said Iran had not yet told it the level at which the second cascade would be enriched. Iran has not yet publicly acknowledged the new cascade.
The 2015 nuclear deal banned all enrichment in Ford. Protected by mountains, the facility is surrounded by anti-aircraft guns and other fortifications. It is the size of a football field large enough to hold 3,000 centrifuges, but small enough and hardened to make US officials suspect a military target when they discovered the site in public in 2009.
U.S. State Department spokesman Ned Price said America remains concerned that Iran continues to deploy advanced centrifuges far beyond what is stipulated in the “nuclear deal.”
“The decay time of fissile material has been drastically reduced from about a year to what can now be measured in weeks or less. “We are deeply concerned about the current state of Iran’s nuclear program,” he said. “That is why we want to see those strict restrictions that the inspection and surveillance regime has imposed on Iran again.”
Amid the tension, Israel is suspected of carrying out a series of attacks inside and outside Iran against the country, including the assassination of the architect of his one-time military nuclear program with remote controlled machine gun.
On Tuesday, the state news agency IRNA quoted the prosecutor of Iran, Southeast Sistan and Balochistan province as saying that three people arrested there in April on suspicion of working with Israel’s Mossad intelligence agency wanted to kill Iranian nuclear scientists.
It is unclear why the three would be in Sistan and Baluchistan, where there are no nuclear facilities. The troubled province, bordering Afghanistan and Pakistan, faces sporadic attacks by armed rebel groups.
Meanwhile, a brigadier general of the guard admitted that the fatal explosion in May at a weapons development facility in Parchin, east of Tehran, came from “industrial sabotage.” Mohammadra Hassani Ahangar, head of Imam Hossein Guard University, said in comments quoted Monday night by a branch of state television that an unnamed enemy had launched the sabotage, which killed an engineer and wounded another worker amid alleged Israeli attacks.
Associated Press authors Amir Wahdat of Tehran, Iran, and Matthew Lee in Washington contributed to the report.
Follow Jon Gambrell on Twitter at www.twitter.com/jongambrellAP.