( CNN ) -- The United States and Mexico agreed Monday to work cooperatively on exploring and developing oil and natural gas reserves along their maritime border . U.S. Secretary of State Hillary Clinton and Interior Secretary Ken Salazar attended the signing of the pact known as the Transboundary Agreement in Los Cabos , Mexico , with Patricia Espinosa , the Mexican foreign relations minister . The agreement requires approval by the U.S. and Mexican national legislatures . According to a statement by the U.S . Interior Department , the agreement will open up almost 1.5 million acres of U.S. outer continental shelf to exploration and development of oil and natural gas reserves . The area , roughly the size of Delaware , is estimated by the Interior Department 's Bureau of Ocean Energy Management to contain up to 172 million barrels of oil and 304 billion cubic feet of natural gas , the department statement said . `` This agreement makes available promising areas in the resource-rich Gulf of Mexico and establishes a clear process by which both governments can provide the necessary oversight to ensure exploration and development activities are conducted safely , '' Salazar said in the statement . The Transboundary Agreement creates a framework for Mexico 's state-owned Petroleos Mexicanos ( PEMEX ) to work with U.S. oil and gas companies in developing the maritime boundary area . It follows the commitment last year by U.S. President Barack Obama and Mexican President Felipe Calderon to work out an agreement on developing the maritime border reserves .
The United States and Mexico sign an agreement to cooperate on energy development . The agreement covers oil and natural gas exploration on their maritime border . The Energy Agreement requires approval from both countries ' national legislatures .