UNITED States President Donald Trump said Sunday the US would hit Iran with “force that has never been seen before” if the country retaliated against US and Israeli strikes that killed supreme leader Ayatollah Ali Khamenei. Iran indicated it was “going to hit very hard today, harder than they have ever hit before,” wrote Trump, who has vowed to seek regime change in the Islamic republic, on his Truth Social platform early Sunday. “THEY BETTER NOT DO THAT, HOWEVER, BECAUSE IF THEY DO, WE WILL HIT THEM WITH A FORCE THAT HAS NEVER BEEN SEEN BEFORE!” he said. The bombing campaign by the US and Israel — which followed a massive military buildup in the Middle East unseen since the 2003 invasion of Iraq — killed Khamenei, Iranian state television confirmed on Sunday. Iran has since retaliated, with reported Iranian strikes across the Gulf, including in the Emirati capital Abu Dhabi and near regional US military bases. Trump has said the US bombing will continue “as long as necessary” and noted Khamenei’s killing gives Iranians their “greatest chance” for taking power from the current regime. Iran’s security chief Ali Larijani said the transition process following the killing of supreme leader Ayatollah Ali Khamenei will begin from Sunday. “An interim leadership council will soon be formed. The president, the head of the judiciary and a jurist from the Guardian Council will assume responsibility until the election of the next leader,” said Larijani, the head of Iran’s top security body, the Supreme National Security Council, who was an adviser to Khamenei. “This council will be established as soon as possible. We are working to form it as early as today,” he said in an interview broadcast by state TV. In Baghdad, hundreds of Iraqis attempted Sunday to storm the fortified Green Zone, where the US Embassy is located, after the death of Ali Khamenei, an Agence France-Presse (AFP) journalist reported. “Their attempts had been thwarted so far, but they keep trying,” a security source told AFP. AFP’s journalist said protesters, some holding flags of pro-Iran armed groups, threw stones at security forces, who responded with tear gas. Local media reported protests in other provinces in southern Iraq. Several Iran-backed Iraqi armed groups said Saturday they will not remain “neutral” and will defend the Islamic republic. The powerful group Kataeb Hezbollah said it will attack US bases after two of its fighters were killed in air strikes in southern Iraq. On Saturday, across the UAE, Iran fired 137 missiles and 209 drones at the country, the UAE defense ministry said, with fires and smoke seen at landmarks The Palm and Burj Al Arab. At Abu Dhabi’s airport, at least one person was killed and seven wounded during what authorities called an “incident.” Dubai airport, the world’s busiest for international traffic, and Kuwait’s airport, were also hit. In Qatar, officials said Iran had launched 65 missiles and 12 drones toward the Gulf state, most of which were intercepted, but eight people were injured, with one in critical condition. On the first day of the strikes on Saturday, smoke poured from US bases in Abu Dhabi and Bahrain’s capital Manama, home of the American navy’s Fifth Fleet, witnesses said, with US bases also targeted in Kuwait. The oil-and-gas-rich Arab monarchies, lying just across the Gulf from Iran, are long-term American allies and host a clutch of US military bases. In Manama, the Iranian attacks saw drones and shrapnel slam into residential buildings, with video on social media showing smoke and fire from high-rises. Saturday’s unprecedented barrage also targeted Qatar’s Al Udeid base, the region’s biggest US military base, as well as Riyadh and eastern Saudi Arabia. Thousands of flights have been delayed or canceled in the biggest disruption to global air transport since the Covid pandemic as airlines suspend services to the Middle East following the US and Israeli attacks on Iran. Iran, Iraq, Israel, Syria, Kuwait and the United Arab Emirates all announced at least partial closures of their skies after Saturday’s strikes and Iran launching missiles at capital cities around the wealthy Gulf region. Major carriers from the Middle East, Europe, Asia-Pacific and the United States announced widespread cancellations, leaving thousands of passengers stranded. Notable airlines that canceled services included Emirates, Etihad, Air France, British Airways, Air India, Turkish Airlines and Lufthansa. According to aviation analytics company Cirium, of around 4,218 flights scheduled to land in Middle Eastern countries on Saturday, 966 (22.9 percent) were canceled, with the figure rising above 1,800 if also including outbound flights. For Sunday, 716 flights out of 4,329 scheduled to the Middle East have been canceled, Cirium said. Flight tracking website FlightAware, meanwhile, said more than 19,000 flights had been delayed globally and more than 2,600 were canceled as of early Sunday morning. The airport closures have rippled far beyond the Middle East. Dubai and neighboring Doha sit at the crossroads of east-west air travel, funneling long-haul traffic between Europe and Asia through tightly scheduled networks of connecting flights. With those hubs idle, aircraft and crews remained stranded out of position, disrupting airline schedules worldwide. Airlines across Europe, Asia and the Middle East canceled or rerouted flights to avoid closed or restricted airspace, lengthening journeys and driving up fuel costs. The disruption has been intensified by the loss of Iranian and Iraqi overflight routes, which had grown more important since the Russia-Ukraine war forced airlines to avoid both countries’ airspace.