— When President Obama arrives in the tiny nation of El Salvador this week to talk about security and poverty, he will stand at a crossroads of arms, drug and human trafficking, where homicide rates are soaring and weak governments are struggling without much help against powerful transnational mafias quickly turning Central America into a crisis.

Mexican drug cartels are increasingly exploiting open borders and homegrown gangs in Guatemala, Honduras and El Salvador — the so-called Northern Triangle — to transport and warehouse drug shipments on their way to the United States and to launder their enormous cash profits.

U.S. officials estimate that as much as 50 percent of the illicit drugs destined for the U.S. border may pass through Central America. As Mexico has tightened controls against bulk cash deposits, they have surged in Guatemala. The majority of grenades used in attacks in Mexico have been traced back to El Salvador, Guatemala, Honduras and Nicaragua, U.S.-manufactured relics of the Cold War that have been repurposed by the cartels.

The leaders of El Salvador, Honduras and Guatemala are pressing for more U.S. aid, intelligence and equipment — such as night vision goggles and police training — to deal with the mounting threats amid criticism that the United States has drifted away from its leadership role in the region.

The three Central American governments are trying to put aside old rivalries and shape a multinational security plan, allowing their militaries and police to work together in cross-border patrols and share resources, such as helicopters, bank records and weapons data, to fight money laundering, car theft and arms trafficking.

“Drug trafficking is a regional problem that requires a regional solution,” said Francisco Altschul, El Salvador’s ambassador to the United States.

To work together, Central American diplomats and regional analysts say that the Obama administration needs to help coordinate efforts. But there is consensus that the U.S. government has been slow to respond to the challenges. Mexico, along with Colombia, has gotten almost all of the attention and money.

Of the $260 million appropriated by Congress since 2008 for the Central American Regional Security Initiative, no more than 10 percent has been spent. When U.S. Assistant Secretary of State William Brownfield was in Central America recently to drum up support for a regional security plan, he announced that Honduras was getting an additional $1.75 million in aid, a gesture that some commentators called paltry.

Support from U.S. law enforcement is thin, but increasing, in the region. Though there is growing evidence weapons are disappearing from military armories to be smuggled north into Mexico, there is a single agent from the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) assigned to the seven Central American nations.

“He doesn’t work cases, he does training,” an ATF spokesman said.

“Many of these countries are starting from zero in their fight against these criminal organizations. They have very little experience. They’re incredibly poor, much poorer than Mexico or Colombia, where all the money has gone,” said Steven Dudley, co-founder of InSight, a research group studying organized crime in the Americas with American University.

“The question on the table is what shall be the scale of U.S. participation? What about numbers?” said Michael Shifter, president of Inter-American Dialogue, a policy think tank. “There is concern in Washington that the situation is deteriorating in Central America and that what is happening there is alarming and the United States needs to help, but I think so far the support has been very meager.”

El Salvador’s Foreign Minister Hugo Martinez was in Washington recently to drum up support for a security response, arguing for “a hemispheric approach,” meaning help from not only the United States, but Colombia and Mexico, which has resisted efforts to work in Central America, arguing that it has its hands full, fighting a U.S.-backed military action against the cartels.

After stops at South American economic powerhouses Brazil and Chile, Obama will be met in El Salvador by President Mauricio Funes, a former television journalist whose 2009 victory saw the former revolutionaries with the Frabundo Martí National Liberation Front peacefully take power after years of civil war.

The Funes government, praised by U.S. diplomats as moderate and pragmatic, was picked by the Obama administration to show that the United States was ready to work alongside the left in Latin America and to elbow aside unfriendly governments in Cuba, Venezuela and Nicaragua.

Daniel Restrepo, senior director for western hemisphere affairs, said the Obama trip was a means to highlight “the restoration of American influence and appeal in the Americas, and the effect that that has had in diminishing the space for those who try to make a living politically on an anti-American sentiment.”

Obama is scheduled to visit the tomb of slain Roman Catholic Archbishop Oscar Arnulfo Romero during his visit, a gesture to heal old wounds. The Catholic leader spoke out against the U.S.-backed Salvadoran army during the 12-year civil war. He was assassinated in 1980 as he celebrated mass.