UPDATE: The world’s most wanted terrorist, the Islamic State militant group's leader Abu Bakr al-Baghdadi, was killed in a U.S.-led raid in northwestern Syria, President Donald Trump announced Sunday.

Addressing the nation live from the White House, Trump said al-Baghdadi killed himself and three of his children, detonating a suicide vest as U.S. forces closed in after a "dangerous and daring" raid.

"Last night, the United States brought the world's number one terrorist leader to justice," Trump said. "Abu Bakr al-Baghdadi is dead."

"Capturing or killling him has been the top national security priority of my administration," he said.

Trump said he died "whimpering and crying and screaming all the way" into a dead-end tunnel.

"He reached the end of the tunnel as our dogs chased them down" and then detonated the suicide vest, Trump said.

"He was a sick and depraved man," the president added, "and now he's gone."

No personnel were lost in the operation, Trump said, but a large number of al-Baghdadi's "fighters and companions were killed with them." A military dog was injured during the operation, Trump later said.

Trump added that "test results gave certain, immediate and totally positive identification" the group's leader was killed.

Trump thanked the nations of Russia, Turkey, Syria, Iraq and the Syrian Kurdish forces.

Trump said the American forces landed with eight helicopters, flying over Russian-controlled airspace with their permission.

"We really had great cooperation," he said.

Reports of al-Baghdadi's death had swirled on social media, with Trump himself appearing to hint at the news late Saturday.

Trump personally approved the operation, according to two people familiar with the matter.

Read the full story on NBC News' website.

PREVIOUS STORY: The world’s most wanted terrorist, Islamic State group leader Abu Bakr al-Baghdadi, was the target of a deadly U.S.-led raid in northwestern Syria, sources told NBC News early Sunday.

Forensic testing is underway, but officials believe al-Baghdadi is among the dead, the sources said.

A U.S. Special Ops mission targeted the ISIS leader near Barisha, Syria, overnight. The mission included helicopters, jets and U.S. drones, the sources said.

The U.S. fired from the air and then landed and gathered intelligence, the sources said. Several others were also killed in a convoy. There were no reports of U.S. casualties.

Newsweek was the first to report the raid.

The White House said President Donald Trump will make a statement at 9 a.m. Sunday. It did not provide additional details.

Trump appeared to foreshadow the news late Saturday. “Something very big has just happened!” he said on Twitter.

The news comes amid growing concerns around ISIS' potential resurgence and following the president's decision to pull troops from Syria's border in advance of a Turkish invasion.

After initially announcing U.S. forces would withdraw from northern Syria amid growing chaos in the wake of Turkey's operation, the U.S. has since begun reinforcing some positions in the region in an effort to prevent oil fields from falling into the hands of the extremist group, according to a U.S. defense official.

That operation is being done in coordination with U.S. partners in the Kurdish-led Syrian Democratic Forces (SDF), a key ally in the fight against the extremist group.

Gen. Mazloum Kobani, the SDF's commander in chief, appeared to hail the operation early Sunday.
Al-Baghdadi has led ISIS since 2010. He stood at the pulpit of the great medieval mosque in Mosul in 2014 to declare himself caliph, sovereign over all Muslims.

But until April, he had not been seen for five years.

That month, the group released an 18-minute video in which a bearded man resembling al-Baghdadi appeared sitting cross-legged on the ground with an assault-style weapon propped up against a wall and praised terrorists who carried out Easter bombings of churches in Sri Lanka.

For years, reports have circulated questioning whether al-Baghdadi is alive.

Some reports have claimed that he was killed in U.S. ordered-drone strikes, while others said he was hiding out in remote regions of Syria or Iraq.