The two leaders were meeting Tuesday at Hacienda Temozon, a resort outside Merida on Mexico's Yucatan Peninsula.

CNN: Bush promises push for immigration reform

MERIDA, Mexico (CNN) -- President Bush vowed Tuesday to do all he can to push for changes in U.S. immigration laws, and stressed that he and his Mexican counterpart, Felipe Calderon, were working together on immigration issues.

CNN: Bush promises push for immigration reform

Just two hours before the blast at Pemex headquarters, the company touted its security record at a conference titled "First Congress for Security, Health and Environmental Protection" in the city of Merida in eastern Mexico.

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The United States, as the primary market for drugs coming from and through Mexico, is cooperating with Mexico under the Merida Initiative.

WHITEHOUSE: Strengthen International Partnerships

Mexican Foreign Secretary Patricia Espinosa said the Merida program presents the United States and Mexico with a chance for "unprecedented" cooperation in the war against drugs.

CNN: U.S., Mexico to kick off $1.4 billion anti-drug plan

Most of the funds in the Merida Initiative, which is due to expire in 2011, are allocated to Mexico, with the rest going to other countries in Central America.

BBC: Clinton pledges broader US effort on Mexico drugs gangs