A U.S. special operations raid against an al Qaeda compound in a remote part of Yemen was not delayed because President Obama failed to sign off on the operation before he left office this month, three Pentagon officials told the Washington Examiner.

The timing of the raid instead was determined by "operational" factors, and could not have been launched any earlier than Saturday, officials said. That runs counter to reports that Obama nixed the plan over weak intelligence.

The raid, conducted by the Navy's elite SEAL Team 6 along with commandos from the UAE, was intended to capture members of al Qaeda in the Arabian Peninsula. Their mission included grabbing vital intelligence on the group, which is known for planning attacks against the West, including the 2014 Charlie Hebdo office massacre in Paris.

When Obama was briefed that the optimal time to launch the raid would be eight days after he was out of office, he deferred the decision to President Trump, almost as a "professional courtesy," said one official.

"The president didn't want to lock in the new administration to a risky raid, when there was plenty of time to approve the operation, after Trump was sworn in," the official said.

Two other Pentagon officials with direct knowledge of the planning confirmed that account, saying Obama's decision not to approve the raid in his last days in office was no reflection on the ability of the U.S. military to conduct the operation at the optimum time.

"There were many conditions to take into account, including weather," said one official, while another added, "All you have to do is look at the calendar to see that the 28th was the darkest day of the year," a reference to the lunar cycle that shows a "new moon" on that date.

U.S. special operations troops prefer to operate under the cover of darkness without moonlight to give away their positions.

That account runs counter to a report in The Guardian, which quoted a source saying the attack plan had undergone several reviews, but Obama took a pass because the intelligence was viewed as too weak to act upon.

Pentagon officials said the raid had been months in the planning, and was always envisioned as a "site exploitation" mission in which ground troops go in to recover computers, mobile phones, and other items that can reveal information about the group's members, resources and plans.

While the goal was to gain intelligence, not to kill high-value targets, the SEALs expected to meet some resistance at the site, and so "went in heavy," one official said.

But another official said the special operations forces were surprised by the level of resistance, and ended up being pinned down in a fierce firefight, which required U.S. Marine AH-1 Cobra attack helicopters to suppress fire from the compound.

The ground fire and air attacks left 14 suspected AQAP members dead, including, the Pentagon says, several female combatants.

Chief Petty Officer William "Ryan" Owens was gravely wounded and later succumbed to his wounds, and during the exfiltration of the U.S. commandos, a $70 million V-22 Osprey aircraft crash-landed and had to be destroyed on the ground. The attack reportedly also killed 8-year-old American Nora al-Awlaki, daughter of Anwar al-Awlaki, killed in a 2011 drone strike ordered by Obama.

Monday, White House spokesman Sean Spicer referred to the operation as a "a very successful raid." But after Pentagon officials conceded not everything went as planned, by Wednesday, Spicer was more measured in his assessment.

"It's hard to ever say something was successful when you lose a life," Spicer told reporters during the regular White House briefing. "But you got to understand that Chief Owens, he went back, deployed 12 times because he loved this country and he believed in the mission. And knowing that we killed an estimated 14 AQAP members and that we gathered an unbelievable amount of intelligence that will prevent the potential deaths or attacks on American soil is something that I think most service members understand, that's why they join the service.

"And so, again, I don't think you ever call anything 100 percent success, but what he did for this nation and what we got out of that mission, I think — I truly believe and I know the president believes is going to save American lives."