MEXICO CITY, Dec. 18 (Xinhua) -- Mexico and the United States have jointly pledged to increase and spur investment in South Mexico and Central America as a way to curb mass immigration, Foreign Affairs Minister Marcelo Ebrard said on Tuesday.

Reading a joint declaration, Ebrard said the United States has earmarked 5.8 billion U.S. dollars to pay for institutional reforms and economic development in Central America's poor Northern Triangle comprised of Honduras, Guatemala and El Salvador.

Washington has also committed to boosting private and public investment of 4.8 billion U.S. dollars in Mexico starting in 2019, with 2 billion to be spent on development projects in the poorer southern states, said Ebrard.

Mexico has in turn announced it will earmark 25 billion U.S. dollars over the next five years to spur public works projects and employment in the southern region.

"I think this is good news, very good news, for Mexico. Just to give you a statistic, the commitments made here mean more than doubling foreign investment in south Mexico," he said.

Recent mass migration to the United States by Central Americans fleeing poverty has put the spotlight on the cross-border problem.

"Mexico and the United States are leading the effort, along with regional and international partners, to build a more prosperous and secure Central America, and in that way address the underlying causes of immigration," said Ebrard.

Currently, at least 2,500 mainly undocumented migrants are amassed at the U.S.-Mexico border, hoping to cross into the United States.

Some 6,000 migrants arrived in Mexico's northern border city of Tijuana in November, but thousands have since returned to their countries, discouraged by Washington's crackdown on undocumented migrants, while hundreds have braved illegal crossings.