At least 35 commodity carriers transited the Strait of Hormuz on Monday, a record level since the start of the Middle East war in late February, according to data from the maritime tracking firm Kpler.

The 35 passages represent nearly a third of normal peacetime traffic, which was around 120 per day through the strait, which normally sees around a fifth of the world's oil and gas exports.

The total count for Monday crossings is expected to rise further as ships are detected later by maritime trackers. Vessels will sometimes switch off their location transponders to transit the strait.

Iran's foreign ministry spokesman said Tuesday that there is no plan yet to allow inspectors from the United Nations' International Atomic Energy Agency to return to Iranian nuclear sites that were severely damaged by U.S. and Israeli strikes a year ago, casting doubt on a remark made Monday by Vice President JD Vance.

"We have not had a meeting with the director general of the International Atomic Energy Agency, nor do we have any plans for the agency to inspect Iran's nuclear facilities damaged by the U.S. and Zionist military aggression," Esmaeil Baqaei said at a press conference.

Vance said Monday that Iran had agreed to let IAEA inspectors visit the nuclear sites as soon as this week following talks with Tehran's negotiators. 

It is not clear whether Iran might allow inspections of other nuclear sites in the country, but the one of most interest is likely Isfahan, which was among those struck last year. 

Isfahan is where IAEA officials believe Iran's stockpile of roughly 900 pounds of highly enriched uranium is buried under rubble. The material is enriched to 60% purity, a short technological step away from the 90% required to make a nuclear weapon.

Vice President Vance said he did not feel snubbed by Iran's Foreign Minister Abbas Araghchi when he appeared to skip out on a photo op with him on Sunday. 

"Trust me, I've spent a lot of time dealing with the Iranians over the last few months. Sometimes I find them extremely confusing as negotiators," he told reporters Monday following hours of meetings with Iranian negotiators and mediators in Switzerland.

Vance said there was a "sort of social media firestorm" suggesting the Iranians were going to leave the talks. 

"And then we proceeded to talk to them for like the next nine hours. So I would just encourage the media, mistrust a little bit what you see coming out of Iranian social media. They can be confusing negotiators, but we feel like we're making progress," he said.

Technical talks between Iran and the United States in Switzerland have wrapped up, with negotiating groups to be set up on nuclear issues and sanctions on Tehran, Iran's state media reported Tuesday.

The negotiators "decided that four working groups would be established: (Iran) Sanctions Termination, Nuclear Affairs, (Iran) Reconstruction and Economic Development, and Monitoring and Implementation (of agreements reached)," said the IRNA state news agency, quoting Deputy Foreign Minister Kazem Gharibabadi.