President Donald Trump vowed on Friday to "destroy the vile, criminal" MS-13 gang and others to "liberate" American communities "that are under siege from gang violence" – while pledging to law enforcement that "we have your backs 100 percent."
"For many years, they've exploited America's weak borders and lax immigration enforcement to bring drugs and violence to cities and towns all across America," Trump told officers at Suffolk County Community College in Brentwood, N.Y., on Long Island.
"They're there right now because of weak political leadership, weak leadership, weak policing – and in many cases because the police weren't allowed to do their job.
"I have a simple message to today for every gang member and criminal alien that are threatening, so violently, our people: We will find you, we will arrest you, we will jail you – and we will deport you."
President Trump has made destroying MS-13 a top priority of his administration.
In February, he signed an executive order directing Attorney General Jeff Sessions to take strong action against the street gang.
Sessions traveled to El Salvador on Thursday to meet with his counterpart and members of an international anti-gang task force.
Also known as Mara Salvatrucha, the street gang is believed to have formed in immigrant communities in Los Angeles in the 1980s before entrenching itself in Central America when its leaders were deported.
It recruits middle- and high-school students, who are said to risk violent retribution if they leave.
Authorities estimate the group has tens of thousands of members across several Central American countries and many U.S. states.
MS-13 is noted for its violent tactics, including torturing victims and hacking them with machetes.
It also sends videos of its gruesome crime scenes to the loved ones of their victims.
On Long Island, gang members have killed 20 people between January 2016 and April of this year, including the brutal massacre of four young men that month in a park in Central Islip.
"MS-13 is particularly violent," President Trump said Friday. "They don't like shooting people because it's too quick. It's too fast.
"They have transformed peaceful parks and beautiful, quiet neighborhoods into blood-stained killing fields," he said. "They are animals.
"But we're getting them out," the president continued. "They're going to jails.
"Then, they're going back to their country – or they're going back to their country, period.
"One by one, we're liberating our American towns."
Since January, the Department of Homeland Security has arrested 3,311 gang members across the country in a number of targeted operations, according to Tom Homan, acting director of U.S. Immigration and Customs Enforcement.
"The men and women of ICE are turning the tide in the battle against MS-13," Trump said.
However, the president called on Congress to provide more resources – including funding for hiring 10,000 more ICE officers, more immigration judges and prosecutors, and for building the wall on the U.S. border with Mexico.
"We're going to build it," the president said, noting that Congress this week approved $1.6 billion for phase-one construction that would start in about two years. "The wall is vital.
"We're going to build a real wall," he said. "We're going to build a wall that works."
The Associated Press contributed to this report.