WASHINGTON — Islamic State leader Abu Bakr al-Baghdadi was believed to be dead after a US military raid in Syria's Idlib region, US media reported early Sunday.
Baghdadi may have killed himself with a suicide vest as US special operations forces descended, media said citing multiple government sources.
He was the target of the secretly planned operation that was approved by US President Donald Trump, officials said.
Long pursued by the US-led coalition against the Islamic State, Baghdadi has been erroneously reported dead several times in recent years.
Officials told ABC News that biometric work was underway to firm up the identification of those killed in the raid.
The White House announced Trump would make a "major statement" Sunday at 9am (1300 GMT), without providing details.
Trump earlier tweeted, without explaining, "Something very big has just happened!"
Baghdadi, a native of Iraq and around 48 years old, led Al-Qaeda's branch in Iraq, taking credit for suicide bombings and other attacks targeting Shiites and moderate Sunnis that left thousands dead over 2010-2013.
He then broke with Al-Qaeda and announced his own, more aggressive jihadist group named Islamic State of Iraq and the Levant (alternately, Islamic State of Iraq and Syria) that aimed to establish its own deeply conservative Islamic nation, or Caliphate, on territory straddling the Iraq-Syria border.
The group's rule was notoriously brutal, and it was globally condemned as a "terrorist organization," blamed for the deaths of thousands of civilians -- in summary executions and beheadings — and accused of war crimes.
Baghdadi though was rarely seen.
After 2014 he disappeared from sight, only surfacing in a video in April this year with a wiry grey and red beard and an assault rifle at his side, as he encouraged followers to "take revenge" for IS members who had been killed.
It was seen as a reassertion of his leadership of a group that, while it had lost its physical territory, had spread from the Middle East to Asia and Africa, promoting the violent ideology he preached.
But Baghdadi remained on the run as the US-led coalition slowly destroyed IS and focused on tracking down the leadership. The US State Department posted a $25 million reward for information on his whereabouts.
Under al-Baghdadi, the US State Department said, IS "has been responsible for the deaths of thousands of civilians in the Middle East, including the brutal murder of numerous civilian hostages from Japan, the United Kingdom, and the United States."
In September the group released an audio message said to be from Baghdadi praising the operations of Islamic State affiliates in other regions.
It also called on scattered IS fighters to regroup and try to free thousands of their comrades captured by the US-allied Syrian Democratic Forces in northeastern Syria.
Idlib is known as a bastion of the Syrian operations of Al-Qaeda — a group Baghdadi continued to view as a rival — leaving experts puzzled by the reports that the IS leader died in the northwest province, in Barisha village.
"If Baghdadi was indeed in Barisha, it will be interesting to understand how he managed to even get there (through Syria or through Turkey?), and how it was possible for him to stay there," tweeted Michael Horowitz, a Middle East security analyst with the Le Beck consultancy.