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.

The president surprised Gulf allies by announcing “Project Freedom” on social media Sunday afternoon, the officials said, angering leadership in Saudi Arabia. A call between Trump and Saudi Crown Prince Mohammed bin Salman did not resolve the issue, forcing the president to pause the plan in order to restore U.S. military access to the critical airspace, sources said.