The US military conducted an operation against elusive Islamic State leader Abu Bakr al-Baghdadi on Saturday, a US official said, as US President Donald Trump prepared to make a "major statement" at the White House on Sunday morning.

The official, speaking on condition of anonymity, was unable to say whether the operation against Baghdadi was successful. Newsweek said the operation took place in Syria's northwestern Idlib province and was carried out by special operations forces after receiving actionable intelligence.

The official did not disclose details of the operation and other US officials contacted by Reuters declined to comment. The Pentagon did not immediately respond to a request for comment.

White House spokesman Hogan Gidley announced late on Saturday that Trump would make a "major statement" at 9 a.m. EST (1300 GMT) on Sunday.

Gidley gave no further details.

The president gave an indication that something was afoot earlier on Saturday night when he tweeted without explanation, "Something very big has just happened!"

Trump has been frustrated by the US news media's heavy focus on the Democratic-led impeachment inquiry, which he calls an illegitimate witch hunt.

He has also faced withering criticism from both Republicans and Democrats alike for his US troop withdrawal from northeastern Syria, which permitted Turkey to attack America's Kurdish allies.

Trump was expected to make the statement in the White House Diplomatic Reception Room, which he has used to make a number of major announcements.

Just last week he used the same room to announce that a ceasefire between Turkey and the Kurds had taken hold.