Amid reports of killing of Islamic State leader Abu Bakr al-Baghdadi, US President Donald Trump on Saturday said that "something very big" has happened.
"Something very big has just happened!" Trump tweeted.
This comes after media reported that the US military has killed Baghdadi.
Trump administration, however, has not revealed whether the matter is related to foreign or domestic policy.
Meanwhile, the White House has announced that Trump is scheduled to make a major announcement on Sunday at 9:00 am (local time),but did not give further details.
"The President of the United States will be making a major statement tomorrow morning at 9 o'clock (1300 GMT)," said White House deputy press secretary Hogan Gidley.
Russia Today has cited Newsweek as reporting that the terrorist was killed in a special operation raid in Syria's northwestern Idlib province, greenlighted by Trump about a week ago.
Meanwhile, Fox News has also quoted military sources saying that a "high-value ISIS target" believed to be the Islamic State leader has been killed by U.S.-led forces in Idlib, Syria.
(inputs from agencies)