During the remainder of the 113th Congress, policymakers will likely maintain an interest in Mexico on issues related to cross-border trade, Mexico's participation in the Trans-Pacific Partnership (TPP) agreement negotiations, energy sector and other reforms in Mexico, economic conditions in Mexico, migration, and border issues. Congress may take a more active interest in the opening of Mexico's energy sector to foreign and private investment for the first time in 76 years. President Pena Nieto began his presidency with an ambitious reform agenda. In December 2013, he signed into law a constitutional amendment that will allow oil companies to gain access to untapped oil reserves in Mexico, which are estimated to be as high as 113 billion barrels."