Marco Rubio, the US secretary of state, is to meet Gulf allies on Tuesday and Wednesday in an attempt to reassure them that the US remains committed to their security and the 60-day ceasefire deal struck with Iran last week will not embolden Tehran.

The Gulf is divided over the deal. While Qatar has played a central role in mediating the agreement, some countries – notably the United Arab Emirates, Kuwait and Bahrain – are fearful it hands Iran substantial sums that may be ploughed into its military.

Donald Trump said in a post to his Truth Social platform on Tuesday that the unfrozen assets would be under US control and used to buy food and medical supplies from the US. The US president also claimed Iran had agreed to allow nuclear inspections long into the future, despite statements from Iran that it has not done so.

In his first trip to the region since the US and Israel started the war on 28 February, Rubio will visit the UAE, Kuwait and Bahrain, the state department said. He is also likely to meet officials from the Gulf Cooperation Council regional body.

All three countries, which house large US military bases, have been hit by Iranian missiles, but the US has declined to detail the scale of the impacts. Severe penalties have been imposed on those using social media to reveal the damage.

Trump last week disclosed that the UAE played an active part in mounting counterattacks against Iran, and the Iranian foreign ministry spokesperson, Esmail Baghaei, said Iran believed the UAE, Kuwait and Jordan all helped the US attack Iran.

“We will definitely not abandon this issue. We will both document and demand,” Baghaei said. “The US military presence in the region has shown what consequences and harm it has brought to the region and its countries. We hope that the countries of the region have learned from the experience of the past few months and years.”

The long-term Iranian aim is to persuade the Gulf states to eject the US from the region. In what is still a fluid debate inside Iran and the Gulf, some Iranian voices are calling for a rapprochement with the region, perhaps by forming an alliance with a powerful new grouping of Turkey, Saudi Arabia, Pakistan and Egypt. The Iranian president, Masoud Pezeshkian, flew to Pakistan on Tuesday in his first overseas visit since the war ended.

There have also been signs that the UAE – the Gulf state with the closest economic ties with Iran – is also looking to defuse the crisis in relations with Iran.

In the short term, Iran is expecting roughly $6bn (£4.54bn) of its assets locked in Qatar due to US sanctions to be unfrozen, with another $6bn to be given by Doha as a repayable loan.

Over the next two months Iran can also expect to receive at least $8bn of income since the US Treasury’s decision on Monday to issue a sanctions waiver on Iranian oil exports. The treasury’s waiver document details that the payments can be made in dollars.

Some internal Iranian estimates claim the income from unhindered oil sales –principally to China – could rise to more than $30bn over a year. Iran has long been evading US sanctions by covertly trading with China but at heavily discounted prices.

The shipping monitors Kepler said 36 ships passed through the strait of Hormuz on Monday, the highest traffic volume since 1 March. Iran’s chief negotiator, Mohammad Bagher Ghalibaf, has said he was working with Oman on a long-term agreement to manage the strait. Ghalibaf met the Sultan of Oman on Monday in Muscat.

Tehran and Washington had clashed on Monday over whether – as Trump and the US vice-president, JD Vance, have claimed – unfrozen Iranian assets could only be used to buy US agricultural produce such as soya beans. Iran’s central bank governor, Abdolnaser Hemmati, said the memorandum of understanding did not obligate Iran to spend unfrozen assets on US goods, and purchase decisions would be made on the basis of quality and price.

Iran also disputed claims that Rafael Grossi, the director general of the UN nuclear inspectorate, had been given an Iranian green light to prepare to return to Iran to inspect the damaged nuclear sites.

Previewing what is likely to be a prolonged discussion about the terms of the International Atomic Energy Agency’s return, Baghaei said: “We have neither met with Grossi nor do we have any plans for the agency to inspect the damaged nuclear facilities resulting from the aggression of the United States and the Zionist regime. There is no protocol in this regard. We will continue the current procedure based on the nuclear non-proliferation treaty.”

Previously, Iran had allowed more intrusive inspections under a specially negotiated additional protocol.

Iran also said further work was needed on the establishment of a mechanism to monitor the proposed Lebanon ceasefire. The MOU states that the US, Iran and “their allies in the current war” declare the “immediate and permanent termination of military operations on all fronts, including in Lebanon” – a formulation that clearly gives the impression of trying to bind Israel to an end to operations against Hezbollah.

This could complicate the US-backed Israel-Lebanon ceasefire reached in early June, which stated that any cessation of hostilities must be agreed directly between Israel and Lebanon, and not through a separate track.