US Secretary of State Marco Rubio told Gulf allies on Thursday that any deal with Iran would take their interests into account, as he wrapped up a Middle East trip aimed at selling the Trump administration’s preliminary accord to sceptical regional partners.

Speaking at a meeting of Gulf Cooperation Council (GCC) in Bahrain, home to the US Navy’s Fifth Fleet, Rubio said Washington was seeking an enduring peace with long-time foe Iran that would not undermine the security and prosperity of its allies in the oil-rich region, which fear the accord is too soft on Iran.

Iran fought two of the world’s most powerful armies — the US and Israel — during the conflict and took effective control of the vital Strait of Hormuz, heavily disrupting oil flows and rattling global energy markets and the wider economy.

The war began with US-Israeli strikes on Iran in late February, and Tehran targeted US assets and bases in Gulf countries in retaliation. It, however, has not accepted responsibility for all of those attacks.

At the GCC meeting, Rubio said: “The reality of it is that no country on Earth has the right to charge for the use of international waterways. And that will never be an acceptable condition of any deal. The president’s been fundamentally clear about that.”

Bahrain’s Foreign Minister Abdullatif bin Rashid Al Zayani, who chaired the gathering, welcomed Oman’s announcement of a corridor for the safe passage of vessels through the strait.

Rubio’s three-day tour of the Gulf is the first high-level diplomatic mission since the US-Iran framework agreement last week to end the war on Iran.

He has acknowledged the delicacy of his mission as he seeks to win over Gulf Arab leaders wary that excessive concessions could strengthen Tehran and reshape the region’s security balance and oil flows.

At his previous stops in the United Arab Emirates and Kuwait, Rubio sought to assure officials that the proposed deal was not overly favourable to Iran.

“We’re not going to do anything that undermines the security of our allies, our longstanding allies in the region,” he told reporters in Kuwait.

Conflicting accounts on deal terms

US President Donald Trump said on Tuesday that Iran had agreed to nuclear inspections into “infinity” while Tehran said it had made no such concession in negotiations.

The two countries, which ended a first round of negotiations in Switzerland on Monday, have also offered conflicting accounts about financial incentives for Iran, control of the Strait of Hormuz, and Israel’s parallel strikes in Lebanon.

All six GCC nations — Saudi Arabia, Qatar, Oman, UAE, Bahrain and Kuwait — are strategic US allies that offered some degree of logistical support to Washington during the war.

Together, they make up the backbone of America’s security architecture in the Middle East, and any country rethinking their security relationship with the US could have a significant impact on US military strategy in the region.

The draft US-Iran agreement includes no limits on Iran’s ballistic missiles, a proposed $300 billion reconstruction fund and provisions that could expand Tehran’s regional influence and control over critical oil shipping lanes.

Rubio has said he would not be asking regional allies to contribute to any reconstruction fund during the trip, even as the MoU with Iran suggests that countries in the region would at least be partially responsible for footing the bill.