President Donald Trump spoke Sunday with Crown Prince Mohammed bin Salman of Saudi Arabia regarding last week’s deadly shooting at a U.S. Navy base in Florida, which was perpetrated by a Saudi military trainee and has further strained relations between the kingdom and Washington.

“The Crown Prince reiterated Saudi Arabia’s commitment to working with the United States to prevent a horrific attack like the Pensacola shooting from ever happening again,” the White House said in a statement. “The President thanked the Crown Prince for Saudi Arabia’s assistance with the investigation and continued partnership.”

Trump tweeted Friday that Saudi King Salman bin Abdulaziz Al Saud, the crown prince’s father, had called him “to express his sincere condolences” for the shooting at the Naval Air Station Pensacola that left four dead, including the gunman — who authorities said was a Saudi national attending flight training.

Defense Secretary Mark Esper said Saturday he had ordered a review of procedures for vetting foreign nationals and security on military installations, and White House national security adviser Robert O’Brien said Sunday that the shooting “appears to be a terrorist attack.”

Florida Gov. Ron DeSantis and Rep. Matt Gaetz (R-Fla.), both staunch allies of the president, have had tough words for the kingdom in the aftermath of the shooting. DeSantis said Friday he told Trump that the Saudi government is “going to owe a debt here given that this was one of their individuals,” and Gaetz asserted Sunday that the attack should “inform our ongoing relationship with Saudi Arabia.”

Trump’s weekend phone call could further escalate tensions and result in greater scrutiny of the White House’s diplomatic response to the violence, considering the international scorn the crown prince has faced for the killing of Washington Post columnist Jamal Khashoggi last October.

Although the Central Intelligence Agency has concluded that the crown prince ordered the assassination, Democratic lawmakers have criticized the president for his reluctance to explicitly condemn the royal and place blame on the kingdom.