As special-operations military troops prepared for a firefight about 7,000 miles away, President Barack Obama entered a room in the Washington area early in the afternoon on Sunday to follow along.

Like a page plucked from a Hollywood screenplay, Obama and other principal coordinators for the mission that killed Osama bin Laden convened in a "situation room" to remotely monitor the situation, John Brennan, the U.S. counterterrorism chief, said in a White House news briefing on Monday.

Obama arrived after many of the mission's leaders had assembled there, but the president joined before the attack on bin Laden's mansion in Abbottabad, Pakistan, began, Brennan said.

"We were able to monitor on a real-time basis the progress of the operation, from its commencement, to its time on target, to the extraction of the remains," Brennan said. "We were able to have regular updates to ensure that we had real-time visibility into the progress of the operation."

The mood in the room was anxious because the stakes were so high, Brennan said.

"There were some very tense moments," he said. "We were just saying our prayers that everything would go according to plan."

The White House and Central Intelligence Agency didn't have access to a live audio feed, but they were able to tap other communications, a U.S. official told CNN. There was some live video, though the official declined to elaborate on the nature of that footage.