United States-Mexico Cross-Border Security Act of 2012 - Directs the President, through the National Security Council Interagency Group, to develop a Whole-of-Government Plan in coordination with the government of Mexico to combat Mexican-based transnational criminal organizations.
Establishes the National Security Council Interagency Group composed of representatives at the Deputy Secretary level from the Department of State, the Department of Homeland Security (DHS), the Department of Justice (DOJ), the Department of the Treasury, the Department of Defense (DOD), and the National Security Council (NSC).