Trump National Security Advisor Robert O’Brien said the U.S. will take Saudi Arabia’s promise to cooperate with the FBI “at their word,” as they investigate the deadly Pensacola Navy base shooting.

“The Saudis have promised full cooperation with the investigation,” O’Brien told CBS Sunday on Face the Nation. “We’re going to take them at their word.”

Navy officials identified a Saudi Arabian aviation trainee as the gunman who open fired on Friday, killing three U.S. Naval Aviation Schools Command students and injuring eight others.

O’Brien has says it “appears to be a terrorist attack,” but the FBI has not yet confirmed his claim.

“We don’t know yet if he was acting alone,” O’Brien said Sunday. “It appears that this may be someone that was radicalized, whether it was here ― it’s unclear if he’s got any ties to any other organizations.”

President Donald Trump tweeted Friday that the King of Saudi Arabia had personally called him to express his condolences for the shooting.

“King Salman of Saudi Arabia just called to express his sincere condolences and give his sympathies to the families and friends of the warriors who were killed and wounded in the attack that took place in Pensacola, Florida,” Trump tweeted.

The President continued, “The King said that the Saudi people are greatly angered by the barbaric actions of the shooter, and that this person in no way shape or form represents the feelings of the Saudi people who love the American people.”

However, not everyone was as quick to accept Saudi Arabia’s word at face value.

Rep. Ted Deutch (D-Florida) tweeted that the White House must ensure that Saudi Arabia holds true to their promise to cooperate.

“We need answers about the shooter and how this shooting happened,” Deutch tweeted Sunday. “The WH was quick to share Saudi condolences and condemnation. Now the President must require the Kingdom to give full and transparent cooperation with this investigation.”

Rep. Matt Gaetz (R-Florida), whose district includes Pensacola, said that the shooting will “inform our ongoing relationship with Saudi Arabia.”

“There are Saudis that are currently with us that are being investigated,” Gaetz told ABC’s This Week on Sunday. “I made the point as clearly as I possibly could that we want no interference from the kingdom.”

He continued, “If there are Saudis that we do not have that may have been involved in any way in the planning, inspiration, financing or execution of this, we expect Saudi intelligence to work with our government.”

Many have been critical of Trump’s positive relationship with Saudi Arabia after he refused to implicate their government in the killing of journalist Jamal Khashoggi. The CIA asserted that the Crown Prince of Saudi Arabia had played a key role in Khashoggi’s disappearance.