U.S. President Donald Trump speaks during the Missile Defense Review announcement at the Pentagon in Arlington, Virginia, U.S., January 17, 2019. REUTERS/Kevin Lamarque

WASHINGTON (Reuters) - President Donald Trump said on Friday he will make a “major” announcement on Saturday at 3 p.m. EST (2000 GMT) on “the humanitarian crisis on our southern border” and the partial government shutdown, now in its 28th day.