White House spokesman Hogan Gidley said on Saturday that the US president would make a "major statement" on Sunday morning at 9 a.m. EST (1300 GMT).
Gidley gave no further details.
The announcement comes one hour after Trump tweeted that something "very big" had happened, sending Twitterians into a meltdown since the president did not elaborate.
According to CNBC, the White House initially said that the statement was made by Special Assistant to the President and Deputy Press Secretary Judd Deere.