Aid for Trade Act of 2019 This bill establishes a body to coordinate the use of U.S. foreign aid to build trade capacity in recipient countries and contains other related provisions. The President shall establish an interagency task force to improve effectiveness of trade-capacity-building assistance programs. The task force shall have members from relevant executive branch agencies including the Department of State, the Department of Commerce, and the U.S. Trade and Development Agency. The task force shall (1) review executive branch agency expenditures on trade-capacity-building assistance, and (2) make recommendations to the President as to the appropriate allocations of such funds. The State Department shall (1) have primary responsibility for overseeing and carrying out such assistance programs, (2) prioritize assistance to certain countries such as those that have consistently supported policies that promote the development of private enterprise, and (3) ensure that the programs are not duplicative. The bill also establishes that one goal of each mission to a foreign country shall be to (1) identify local barriers to international trade and investment, (2) advise the State Department on trade-capacity-building assistance, and (3) coordinate and supervise trade-capacity-building assistance programs. The Government Accountability Office shall periodically review the impact of the trade-capacity-assistance programs.