Washington, May 3 (IANS): US President Barack Obama Thursday kicked off a three-day visit to Mexico and Costa Rica, with focus expected to be on trade, energy, security and immigration issues.

On his trip, Obama earlier said, "A lot of the focus is going to be on economics."

"We've spent so much time on security issues between the United States and Mexico that sometimes I think we forget this is a massive trading partner, responsible for huge amounts of commerce and huge numbers of jobs on both sides of the border," Xinhua quoted the president as saying.

"We want to see how we can deepen that, how we can improve that and maintain that economic dialogue over a long period of time," he said.

Mexico, as a member of the North American Free Trade Agreement, which also includes Canada and the US, is America's second largest export market and the third largest trading partner.

Trade between the two countries is worth $500 billion a year. Mexico is also a major source of undocumented migrants as well as drugs to its northern neighbour.

"Mexico is an important partner in immigration reform given that we work with them every day to secure our border," said Ben Rhodes, Obama's deputy national security advisor for strategic communications.

During his first trip to Costa Rica and his sixth to the Latin American region as president, Obama will meet his Costa Rican counterpart Laura Chinchilla, and then attend a summit with leaders of Central American nations, with focus on security, immigration and economic issues.

Washington is helping Mexico and the Central American nations combat drug trafficking and other organized crimes under the so-called Merida Initiative signed by Obama's predecessor George W. Bush, and has put in $1.9 billion since its inception in 2008.