Park Record Media Center

President Barack Obama waves as he arrives to Benito Juarez International airport in Mexico City, Thursday, May 2, 2013. Obama arrived to Mexico for a two-day visit. (AP Photo/Eduardo Verdugo) ( Mexico Obama )

U.S. agents stand on the tarmac as they wait for Air Force One carrying U.S. President Barack Obama to arrive at the presidential hangar at Benito Juarez International Airport in Mexico City May 2, 2013. REUTERS/Tomas Bravo ( MEXICO/ )

President Barack Obama leaves Air Force One upon his arrival at Benito Juarez International Airport in Mexico City, Thursday, May 2, 2013. Obama is traveling on a three-day trip to Mexico an Costa Rica. (AP Photo/Pablo Martinez Monsivais) ( Obama US Mexico )

President Barack Obama, center, walks on the tarmac to his vehicle upon his arrival at Benito Juarez International Airport in Mexico City, Thursday, May 2, 2013. Obama is traveling on a three-day trip to Mexico an Costa Rica. (AP Photo/Pablo Martinez Monsivais) ( Obama US Mexico )

U.S. President Barack Obama (3rd R) alights from Air Force One as he begins his visit to Mexico City May 2, 2013. Obama arrived in Mexico on Thursday for a visit he hopes will draw attention to Mexico's emerging economic might, even as worries about containing drug-trafficking and related violence remain an inescapable subtext. REUTERS/Kevin Lamarque ( USA-OBAMA/MEXICO )

Riot Police officers stand guard outside the US embassy in Mexico City as people demonstrate during a protest organized by the Meso-American Migrant Movement to demand the deportation of Mexicans from the US to stop, on May 2, 2013. Migration will be among the top issues when US President Barack Obama visits Mexico and Costa Rica this week, and many in the region hope Washington will finally act to give 11 million undocumented workers a path to citizenship. Obama headed to Mexico on Thursday to put trade back at the heart of bilateral ties, but his southern neighbour's shifting drug war tactics loom large over the visit. YURI CORTEZ/AFP/Getty Images ( 519419735 )

Picture of part of the safety convoy of US President Barack Obama as he is driven through Mexico City, on May 2, 2013. Obama landed in Mexico on Thursday at the start of a three-day trip that will also take him to Costa Rica, with trade, US immigration reform and the drug war high on the agenda. The runways of Mexico City's international airport closed for half an hour to let Air Force One land, and Obama was scheduled to head to the historic National Palace downtown for talks with Mexican President Enrique Pena Nieto. HECTOR GUERRERO/AFP/Getty Images ( 519422265 )

US President Barack Obama (inside armored vehicle) arrives at Zocalo Square moments after landing on Mexican soil on May 2, 2013. Obama landed in Mexico on Thursday at the start of a three-day trip that will also take him to Costa Rica, with trade, US immigration reform and the drug war high on the agenda. The runways of Mexico City's international airport closed for half an hour to let Air Force One land, and Obama was scheduled to head to the historic National Palace downtown for talks with Mexican President Enrique Pena Nieto. HECTOR GUERRERO/AFP/Getty Images ( 519422126 )

Demonstrators protest outside the U.S. embassy before the arrival of President Barack Obama in Mexico City, Thursday, May 2, 2013. The protesters are from an organization that represents people who used to be part of a workers program between Mexico and the U.S. called "Braceros," members of the Mexican Union of Electricians (SME) and pro-migrant groups. (AP Photo/Marco Ugarte) ( Mexico Obama Protest )

Demonstrators protest outside the U.S. embassy before the arrival of President Barack Obama in Mexico City, Thursday, May 2, 2013. The sign at center reads in Spanish "Listen Obama. Don't plant your weapons in Mexico! Don't separate our families! Keep your promise : Migration reform now!" The protesters are from a former worker program called "Braceros," members of the Mexican Union of Electricians and a pro-migrant organization. (AP Photo/Marco Ugarte) ( Mexico Obama Protest )

A member of the Meso-American Migrant Movement hangs banner in front of the US embassy in Mexico City during a protest to demand the deportation of Mexicans from the US to stop, on May 2, 2013. Migration will be among the top issues when US President Barack Obama visits Mexico and Costa Rica this week, and many in the region hope Washington will finally act to give 11 million undocumented workers a path to citizenship. Obama headed to Mexico on Thursday to put trade back at the heart of bilateral ties, but his southern neighbor's shifting drug war tactics loom large over the visit. YURI CORTEZ/AFP/Getty Images ( 519419479 )

Demonstrators protest outside the U.S. embassy before the arrival of President Barack Obama in Mexico City, Thursday, May 2, 2013. The sign at left reads in Spanish "President Barack Obama : In Mexico there are no jobs and the few that exits the government takes them from us." The protesters are from an organization that represents people who used to be part of a workers program between Mexico and the U.S. called "Braceros," members of the Mexican Union of Electricians (SME) and pro-migrant groups. (AP Photo/Marco Ugarte) ( Mexico Obama Protest )

People hold signs calling for the U.S. government to halt deportations of immigrants during a protest outside the U.S. embassy in Mexico City May 2, 2013. U.S. President Barack Obama is scheduled to arrive in Mexico on an official visit. REUTERS/Claudia Daut ( MEXICO )

A Mexican Federal policeman patrols with his sniffer dog at Zocalo Square, hours before the arrival of US President Barack Obama in Mexico City, Mexico on May 02, 2013. Obama headed to Mexico on Thursday to put trade back at the heart of bilateral ties, but his southern neighbor's shifting drug war tactics loom large over the visit. HECTOR GUERRERO/AFP/Getty Images ( 519419939 )

U.S. and Mexican (C) flags are displayed at the National Palace where U.S. President Barack Obama and his Mexican counterpart Enrique Pena Nieto were meeting, in Mexico City May 2, 2013. Obama arrived in Mexico on Thursday for a visit he hopes will draw attention to Mexico's emerging economic might, even as worries about containing drug-trafficking and related violence remain an inescapable subtext. REUTERS/Kevin Lamarque ( USA-OBAMA/MEXICO )

US President Barack Obama (2-L) and Mexican President Enrique Pena Nieto (3-L) make their way to their seats for a bilateral meeting on May 2, 2013 at the Palacio Nacional in Mexico City. Obama landed in Mexico on Thursday at the start of a three-day trip that will also take him to Costa Rica, with trade, US immigration reform and the drug war high on the agenda. The runways of Mexico City's international airport closed for half an hour to let Air Force One land, and Obama was scheduled to head to the historic National Palace downtown for talks with Mexican President Enrique Pena Nieto. MANDEL NGAN/AFP/Getty Images ( 519421839 )

President Barack Obama, right, and Mexico's President Enrique Pena Nieto, left, takes the seats before their bilateral meeting at the Palacio Nacional Salon de Recepciones in Mexico City, Thursday, May 2, 2013. (AP Photo/Pablo Martinez Monsivais) ( Obama US Mexico )