President Felipe Calderon welcomed seven new ambassadors, including new U.S. envoy to Mexico Earl Anthony Wayne, to the Los Pinos presidential residence, where he received their credentials.

Wayne replaces Ambassador Carlos Pascual, who resigned in March after Calderon blasted him for comments the envoy made in diplomatic cables obtained and disseminated by WikiLeaks.

The new ambassador must mend fences in the wake of the clashes between Pascual and the Calderon administration, as well as the fallout from "Operation Fast and Furious," a U.S. operation that allowed thousands of firearms to be smuggled into Mexico in an effort to trace the weapons to the highest levels of Mexico's drug cartels.

U.S. authorities lost track of hundreds of the weapons, one of which was used to kill a U.S. federal agent.

Pascual questioned the capabilities of the Mexican army and whether it could effectively conduct the fight against drug trafficking in a diplomatic cable released by Wikileaks.

Wayne spoke with reporters after presenting his credentials on Tuesday at Los Pinos, telling the press that his priority was to bolster bilateral relations and work on the Merida Initiative, a $1.4 billion security cooperation pact aimed at fighting drug trafficking and other forms of transnational organized crime.

"To achieve this end, our cooperation efforts remain the central focus of our shared agenda to offer security to our communities on both sides of the border via the Merida Initiative," Wayne said.

The United States and Mexico can work together "to halt the illegal flow across the border in both directions of arms and explosives, narcotics, illicit money, people trafficking and all the other goods that organized crime groups smuggle and that do so much harm to both peoples," the ambassador said.

Wayne, who had been the No. 2 diplomat at the U.S. Embassy in Afghanistan since May 2010, joined the Foreign Service in 1975 and was named a career ambassador in December 2010, one of the highest honors in the State Department.

He served as U.S. ambassador to Argentina from 2005 to 2009.