Vietnam Veterans Memorial Visitor Center Deadline Enforcement Act - Amends federal law which authorized construction of a Vietnam Veterans Memorial Visitor Center (Center) in Washington, D.C. to require: (1) the Center to be located underground in the triangular land area between Henry Bacon Drive, 23rd Street, Constitution Avenue, and the Lincoln Memorial; and (2) final approval for the Center no later than 30 days after the enactment of this Act.