President Trump touted his immigration policies during a meeting with manufacturing CEOs, saying, "We're getting really bad dudes out of this country," including criminals and gang members, in what he called "a military operation," on Feb. 23 at the White House. (The Washington Post)

President Trump on Thursday celebrated what he called “a military operation” to round up and deport undocumented immigrants who have committed crimes or caused violence in the United States.

“We’re getting gang members out, we’re getting drug lords out, we’re getting really bad dudes out of this country — and at a rate that nobody’s ever seen before,” Trump told a group of several dozen manufacturing executives during a policy discussion at the White House.

Trump brought up immigration enforcement as he discussed the trip Secretary of State Rex Tillerson and Homeland Security Secretary John Kelly are taking to Mexico this week. Trump said he told Tillerson, “That’s going to be a tough trip, because we have to be treated fairly by Mexico.”

Trump then praised Kelly for the work his department is doing to secure the border with Mexico and deport illegal immigrants.

“It’s a military operation,” Trump said, attributing gang violence and illegal drug trade to undocumented immigrants.

Trump was presumably referring to actions carried out by U.S. Immigration and Customs Enforcement (ICE) two weeks ago that rounded up 683 immigrants purportedly in the country illegally.

[Trump administration issues new immigration enforcement policies, says goal is not ‘mass deportations’]

Trump's reference to a military operation could raise eyebrows among immigrant rights advocates and even within the Department of Homeland Security. Federal immigration policy is enforced by several divisions inside DHS, including Customs and Border Protection and ICE, and the military has no role. A leaked DHS proposal last week to deploy Army National Guard troops to help apprehend undocumented immigrants was quickly denied by DHS leadership and the White House as being under consideration. The unions representing Border Patrol agents and officers have regularly denounced the use of military personnel.

“I do not believe the National Guard to be a good idea,” Brandon Judd, president of the National Border Patrol Council, said in an interview. “We’re just setting ourselves up for too much liability with people who have not been trained to do the jobs.”

White House press secretary Sean Spicer said Trump used the phrase “military operation” as a way to describe how the raids were being conducted, not to suggest that they are being done by the military.

“The president was using that as an adjective,” Spicer said at his Thursday afternoon news briefing. “It's happening with precision … The president was clearly describing the manner in which this is being done.”

Kelly said unequivocally Thursday that there would be no mass deportations and that the raids are targeting only “the criminal element.”

“Let me be very clear. There will be no — repeat, no — mass deportations,” Kelly said at a news conference in Mexico City. “Everything we do in DHS will be done legally and according to human rights” and the U.S. law.

Kelly added, “There will be no — repeat, no — use of military force in immigration operations. None. Yes, we'll approach this operation systematically, in an organized way, in a results-oriented way, in an operational way, in a human dignity way... [but] there will be no use of military forces in immigration.”

While Trump said the number of criminals being rounded up is “at a rate that nobody's ever seen before,” similar raids were carried out during the Obama administration and Kelly's department played down the significance of the number of people arrested in a Feb. 13 news release.

“ICE conducts these kind of targeted enforcement operations regularly and has for many years,” DHS said.

But immigrant rights advocates have said directives contained in a pair of memos from Kelly this week would significantly expand the pool of immigrants who would be targeted for deportation, broadening it well beyond the hardened criminals and new arrivals that had been the priorities under the Obama administration.

On Thursday, Trump portrayed the immigrants targeted as hardened criminals.

“They’re rough and they’re tough, but they’re not tough like our people, so we’re getting them out,” Trump said.

David Nakamura and Karen DeYoung contributed to this report.