By Gram SlatteryAbu Dhabi — US secretary of state Marco Rubio held talks with top UAE officials on Wednesday on a Middle East tour, seeking to reassure Gulf allies who view a proposed Iran peace deal as too soft on a state that attacked them in the war.The US-Iran accord reached last week — the first signed by an American and an Iranian president since Iran’s 1979 Islamic Revolution — includes a proposed $300bn fund and the waiver of some sanctions.Arriving in the UAE capital Abu Dhabi late on Tuesday for a three-day tour of the oil-rich Gulf, Rubio is undertaking his first high-level diplomatic mission on the agreement to end the four-month US-Israeli war with Iran.Rubio held a working lunch with UAE President Sheikh Mohammed bin Zayed Al Nahyan and other senior figures, including national security adviser Sheikh Tahnoun bin Zayed Al Nahyan and foreign minister Sheikh Abdullah bin Zayed Al Nahyan.Allies’ disquietAsked on arrival if he planned to address allies’ disquiet with the accord, Rubio told reporters: “That most certainly will come up in these discussions.” He said they would also discuss issues not covered by the memorandum of understanding.America’s top diplomat has been largely absent from Iran-related discussions in recent weeks, with vice-president JD Vance instead leading a round of talks with Iranian counterparts over the weekend in Switzerland.As well as the UAE, Rubio is also visiting Kuwait and Bahrain. All three nations host strategic US military bases and were hit by an onslaught of Iranian missiles, resulting in civilian deaths.The UAE faces particularly severe economic strains, as the war caused some expatriates at the core of its non-oil economy to flee the global financial centre, which prides itself on stability in a volatile Middle East.Qatari ‌Prime Minister Sheikh Mohammed bin Abdulrahman al-Thani visited Muscat on Wednesday for talks with Oman on initiating negotiations involving Iran, Iraq and Gulf Arab states on the Strait of Hormuz, a diplomat briefed on the talks told Reuters. The discussions are separate from US-Iran peace talks.The Strait of Hormuz, a vital route for roughly a fifth of global oil and liquefied natural gas supplies, has been heavily disrupted since the US and Israel launched a war against Iran on February 28, curbing commercial shipping and rattling global energy markets.Separately, there are plans for regional reconciliation talks to be held in Riyadh between Iran, Gulf Arab states and possibly other regional countries.Rubio’s remarks during his swing through the region will be closely scrutinised to see how the man once known as a hawkish critic of Iran frames a deal that many congressional Republicans argue amounts to capitulation.Rubio and Vance, both former US senators, are widely viewed within Republican Party circles as potential candidates to succeed Trump.Interim accordRubio’s mission is delicate: While he needs to defend a preliminary accord that Trump firmly supports, he also has to credibly address the concerns of his Gulf counterparts.Iran and the US signed a 14-point memorandum of understanding last week setting out broad agreements in principle to end the war. The interim accord paved the way for 60 days of talks aimed at hammering out thornier details, including issues related to Iran’s nuclear programme.A central issue in talks is what will happen to Iran’s highly enriched uranium, including material enriched to up to 60% purity, a short step from the roughly 90% of weapons grade. Tehran says its nuclear programme is for peaceful purposes.US regional allies are especially concerned that Iran could use the proposed $300bn reconstruction fund to rebuild its military. The accord also does not address Tehran’s ballistic missile capacity, a concern for Gulf states, which were struck by Iranian missiles and drones in the war.