D.C. Code § 9-903
The Authority created by this chapter is authorized, when similarly authorized by the Commonwealth of Virginia, to acquire from the United States of America, by lease or otherwise, the 2 airports known as Washington National Airport and Washington Dulles International Airport and all related properties now administered by Metropolitan Washington Airports, and agency of the Federal Aviation Administration of the United States Department of Transportation, but only with the approval of the Mayor of the District of Columbia. Subject to this mayoral approval, general consent is given to conditions imposed by the Congress of the United States on acquisitions that are not inconsistent with this chapter. The Mayor shall procure the concurrence of the Council of the District of Columbia, by resolution, prior to Mayoral approval of the terms of the compact, lease or other agreements which effectuate the acquisition.
D.C. Code § 9-903