U.S. President Donald Trump has accused El Salvador of stealing U.S. dollars intended for anti-drug trafficking initiatives, while insisting Mexico's loose border is aiding the movements of Central American gang members.
"MS-13 gang members are being removed by our great ICE (Immigration and Customs Enforcement) and Border Patrol Agents by the thousands, but these killers come back in from El Salvador, and through Mexico, like water," Trump posted on his Twitter account.
"El Salvador just takes our money, and Mexico must help MORE with this problem. We need The Wall," he wrote.
The MS-13 gang has expanded significantly in recent years, with more than 10,000 members now spread across 40 U.S. states, Attorney General Jeff Sessions said in December, calling the group one of America's "most dangerous gangs."
During a roundtable discussion on gun violence Thursday, Trump said: "We're getting them out by the thousands, putting them in jail and we're getting them out by the thousands, and our people from ICE and our Border Patrol people are much tougher than they are.
"That's the only thing they understand, by the way, is toughness."
M-13 was started by Salvadoran immigrants on the west coast in the 1980s and has since spread throughout Central America and the United States.
Deportation only seems to strengthen the gang: members sent back to Central America promptly enlist new recruits before slipping back into the United States, the LA Times explained in a 2005 report.
The Trump administration has used the gang as a talking point to criticize immigration policies, labeling members "animals" guilty of transforming "peaceful parks and beautiful, quiet neighborhoods into bloodstained killing fields."
Critics, however, are warning that calling attention to the gang, also known as Mara Salvatrucha, only serves to strengthen it.
A study published in Insight Crime earlier this month concluded that "In the United States, the federal government has made MS-13 a center-point of its immigration policy, which has bolstered the gang's image as the most feared gang in the region.
"The gang will take advantage of this political capital when it is handed to it."
MS-13 works as a nebulous social group, without any single leader or leadership structure and composed primarily of teenagers. Long Island police say the group is responsible for numerous murders, including a quadruple homicide in 2017.
The report criticizes the current U.S. administration for failing to provide significant guidance to youths forced to turn to gang life for protection rather than the federal government.
It also notes that the United States has so far only exercised the same failed techniques previously tried in Central America and recommends Washington should utilize other strategies to eliminate the gang.