Washington CNN  — 

Retired Adm. William McRaven, a former Navy SEAL who led US Joint Special Operations Command from 2011 to 2014, said Thursday that he has serious doubts about President Donald Trump’s claim that he called off retaliatory strikes on Iran at the last minute because that is when he learned there would be casualties.

“We were cocked & loaded to retaliate last night on 3 different sights (sic) when I asked, how many will die. 150 people, sir, was the answer from a General … 10 minutes before the strike I stopped it,” Trump tweeted at the time.

McRaven, who oversaw the 2011 raid that killed Osama bin Laden, told reporters that he was ultimately happy with the President’s last moment decision not to carry out the strikes after the downing of a US drone in June and agreed it would not have been a proportional response.

However, the retired admiral made it clear that he found it “hard to believe” Trump stopped the strike at the last minute upon learning that there would be casualties. Drawing on his experience in similar situations, McRaven said the casualty count is typically part of the detailed briefing given to the president and national security adviser when they first request military options.

“When I heard, after the fact, that it was only at the last minute that the President realized there would be casualties, frankly, I find that hard to believe because the casualty count is almost always part of the military’s briefing when it comes to a strike on a target,” McRaven told reporters during a call about a new report from the nonprofit International Crisis Organization focused on Iran.

“So this idea that it was only through the President’s restraint that we got as far as we did, I think the bigger question is: Why did we get that far?” he added. “I am hard pressed to believe that he was not briefed ahead of time about what the casualties would be.”

McRaven, who resigned as chancellor of the University of Texas at Austin last year, is widely respected among the tens of thousands of active and retired special operators. He has also been openly critical of Trump, drawing the President’s ire for an opinion piece published in The Washington Post last August.

In that op-ed, McRaven issued a stunning rebuke of Trump’s decision to revoke the security clearance of former CIA Director John Brennan and volunteered to have his own security clearance revoked in an act of solidarity.

“Through your actions, you have embarrassed us in the eyes of our children, humiliated us on the world stage and, worst of all, divided us as a nation,” he said of Trump at the time.

“If you think for a moment that your McCarthy-era tactics will suppress the voices of criticism, you are sadly mistaken. The criticism will continue until you become the leader we prayed you would be,” McRaven added.

Trump responded by calling the four-star admiral “a Hillary Clinton backer and an Obama backer” and said it would “have been nice if we got Osama bin Laden a lot sooner than that.”

CORRECTION: This story and headline have been updated to correctly describe how McRaven said he doubted Trump’s claims that the Iran strikes were called off just minutes before they were set to occur because he learned of expected casualties.