And thousands of miles away in the White House Situation Room, President Donald Trump says he witnessed Islamic State leader Abu Bakr al-Baghdadi's end on video in amazement.

"As though you were watching a movie," he said.

In extended questions and answers Sunday after announcing the raid, Trump said that Baghdadi had been "under surveillance for a couple of weeks."

As soon as confirmation came in about his location, the raid by special forces swung into motion Saturday.

"A large group" took part, with "eight helicopters, and we had many other ships and planes," Trump said.

First, they had to cross hostile territory from a still-undisclosed location into northwest Syria, flying about one hour and 10 minutes.

"We flew very, very low and very, very fast. But it was a big -- it was a very dangerous part of the mission. Getting in and getting out," Trump said.

"There was a chance that we would have met unbelievable fire," he said.

And when they landed at the targeted compound, "all hell broke loose," according to Trump.

- 'Only one person' left -

"A large crew of brilliant fighters ran out of those helicopters and blew holes into the side of the building" to avoid booby traps in any doors, he said.

That "was something really amazing to see," he said about his experience in the Situation Room, where he was joined by Vice President Mike Pence and senior military and national-security officers. "We watched it so clearly."

"They were greeted with a lot of firepower," he said.

A "large number" of Baghdadi's supporters died in the return fire, Trump said, but no US troops.

Commanders relayed back their progress, step by step: Eleven children had been taken out alive, they said. Prisoners were being taken. Baghdadi's wives were dead.

And then came the call everyone was waiting for.

"Sir, there's only one person in the building. We are sure he's in the tunnel trying to escape but it's a dead-end tunnel," Trump recounted being told.

It was Baghdadi.

Knowing beforehand that there would be tunnels and that the fugitive was likely wearing a suicide vest, the US forces had brought a robot. But it never got used.

"We were moving too fast," Trump said. "They were chasing."

Baghdadi had taken three of his children down into the tunnel, Trump said. Their presence wasn't going to stop the inevitable, though.

"It was brutal," Trump said.

The US troops sent dogs down the tunnel and the Islamic State mastermind "blew himself up."

"He reached the end of the tunnel as our dogs chased him down. He ignited his vest, killing himself and the three children," Trump said.

"He didn't die a hero, he died a coward, crying, whimpering and screaming and bringing three kids with him to die. Certain death. And he knew the tunnel had no end," Trump said.

The US soldiers took samples from the mutilated leader's body for DNA identification, loaded back up and left.

Trump said the troops were in the compound for about two hours.

"We lost nobody, think of that," he said.

There was one casualty on the US side, in fact.

"Our dog was hurt," he said.