Head coach Richie Williams' team conceded twice in the second half to lose its World Cup debut.
The United States lost 2-0 to Nigeria in its U-17 World Cup opener in Santiago, Chile on Saturday afternoon.
Five minutes into the second half, Nigeria opened the scoring. Auston Trusty failed to clear a cross from the right side and the loose ball fell to Chukwudi Agor, who slammed home from close range.
The lead was doubled 10 minutes later, as Victor Osimhen beat the two U.S. center backs and slotted home off the post when one-on-one with U.