Trump's choice will fill a vacancy left by the sudden death last year of conservative Justice Antonin Scalia.
Trump's choice will fill a vacancy left by the sudden death last year of conservative Justice Antonin Scalia, which left the court evenly divided between four conservative and four liberal justices.
"I have made my decision on who I will nominate for The United States Supreme Court. It will be announced live on Tuesday at 8:00 P.M. (W.H.)," Trump said on his Twitter account.
Abortion, gay marriage, gun control -- the Supreme Court is the final arbiter of many of the most sensitive issues of American life and law.
Its members, who must be confirmed by the Senate, are named to life terms so their influence is long lasting.
Trump has said he wants a candidate who is against abortion and firmly backs Americans' right to own guns.
Among those tipped as frontrunners for the post are Neil Gorsuch, a respected appellate court judge who is considered an ideological match to Scalia, and William Pryor, an Alabama appellate court judge considered an opponent of abortion rights.
Trump had said he would announce his pick on Thursday, but has moved the date up amid a raging controversy and confusion over his order to temporarily bar travelers from seven predominantly Muslim countries from entering the United States.
His Supreme Court pick is certain to set off another pitched battle with Democrats.
Former president Barack Obama had named Merrick Garland, an appellate court judge, to fill Scalia's seat but Republicans used their control of the Senate to keep his nomination from being considered.