BRASILIA ARRIVAL U.S. Ambassador to Brazil Thomas A. Shannon Jr., left, greets U.S. Defense Secretary Leon E. Panetta upon his arrival in Brasilia, Brazil, April 24, 2012. Panetta is on a five-day trip to the region to meet with counterparts and military officials in Colombia, Brazil and Chile to discuss an expansion of defense and security cooperations. SHARE: Download: Full Size (0.05 MB) Credit: VIRIN: 236281-Z-LHN74-643.jpg Photo Gallery