In 2002, he was appointed U.S. Ambassador to Mexico, a position he held until 2009. In 2009, the year he retired from the office, Garza received the Águila Azteca from Mexico in recognition of his work to strengthen the bonds between Mexico and the United States. This is the highest award that Mexico bestows on foreigners. Thereafter, he took a position as counsel with White & Case LLP and also as chairman of management consultancy firm Vianovo Ventures.