WASHINGTON — President Donald Trump’s abrupt reversal on his plan to help ships go through the Strait of Hormuz came after a key Gulf ally suspended the U.S. military’s ability to use its bases and airspace to carry out the operation, according to two U.S. officials.

Trump surprised Gulf allies by announcing “Project Freedom” on social media Sunday afternoon, the officials said, angering leadership in Saudi Arabia. In response, the Kingdom informed the U.S. it would not allow the U.S. military to fly aircraft from Prince Sultan Airbase southeast of Riyadh or fly through Saudi airspace to support the effort, the officials said.

A call between Trump and Saudi Crown Prince Mohammed bin Salman did not resolve the issue, the two U.S. officials said, forcing the president to pause Project Freedom in order to restore U.S. military access to the critical airspace.

Other close Gulf allies were also caught off guard; the president spoke with leaders in Qatar after the effort had already begun.

A Saudi source told NBC News that Trump and the crown prince “have been in touch regularly.” Saudi officials were also in touch with Trump, Vice President JD Vance, U.S. Central Command and Secretary of State Marco Rubio, the source added.

Asked whether the announcement of Project Freedom caught the Saudi leaders by surprise, the Saudi source said: “The problem with that premise is that things are happening quickly in real time.” The source said Saudi Arabia was “very supportive of the diplomatic efforts” by Pakistan to broker a deal between Iran and the U.S. to end the war.

A White House official said in a statement when asked about some Gulf state leaders being caught off guard by the announcement of the U.S. effort to help ships transit the Strait of Hormuz, “Regional allies were notified in advance.”

A Middle Eastern diplomat said the U.S. did not coordinate Project Freedom with the Omanis until after Trump made the announcement. “The U.S. made an announcement and then coordinated with us,” the diplomat said, adding, “we were not upset or angry.”

Trump had announced the operation over the weekend as a way to break Iran’s blockade in the Strait of Hormuz, and his top national security leaders spent much of Tuesday talking up the effort in public briefings at the Pentagon and White House, only to have the president suddenly halt the operation roughly 36 hours after it began.

The U.S. military had been lining up a number of additional ships in the Gulf for transit through the strait when the operation was stopped, a U.S. official said. U.S. Central Command had earlier announced that two U.S. flagged ships had made it through the strait as part of Project Freedom.

In his post, Trump said Project Freedom would be “paused for a short period of time to see whether or not” an agreement to resolve the war “can be finalized and signed.”

The U.S. military maintains fighter aircraft, refueling tankers and air defenses at Prince Sultan Airbase in Saudi Arabia. The Saudis allowed the U.S. to fly aircraft from there to support the war in Iran, as well as allowing aircraft based in nearby countries to fly over.

“Because of geography, you need cooperation from regional partners to utilize their airspace along their borders,” one U.S. official said. In some cases there is no other way around, the official explained. Military aircraft were critical to protect ships during Project Freedom, essentially providing a defensive umbrella.

The U.S. military refers to permission to use another country’s territory as ABO, which stands for access, basing and overflight. Fighter jets, refueling tankers and support aircraft all need permission to fly from key regional allies. Saudi Arabia and Jordan are critical for allowing aircraft to base there, Kuwait is critical for overflight, and Oman for both overflight and naval logistics.

Trump called the emir of Qatar after Project Freedom began, and a Qatari official said in a statement that they discussed the ceasefire agreement and “implications for maritime security and global supply chains.” The statement said the emir emphasized the importance of de-escalation.

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