Rep. Alexandria Ocasio-Cortez accused President Donald Trump's administration of running "concentration camps" in its detention of migrants at the southern border.

Conservatives quickly slammed the New York Democrat for her use of the term, which is most commonly associated with Nazi death camps during the Holocaust.

"The United States is running concentration camps on our southern border, and that is exactly what they are -- they are concentration camps," Ocasio-Cortez told an Instagram Live audience Monday evening. "And if that doesn't bother you ... I want to talk to the people that are concerned enough with humanity to say that we should not, that 'never again' means something," a reference to a phrase commonly invoked by Jews about the Holocaust.

"The fact that concentration camps are now an institutionalized practice in the home of the free is extraordinarily disturbing, and we need to do something about it," she added.

Ocasio-Cortez also referenced how some migrant children were being held in facilities formerly used to detain Japanese Americans during World War II. Last week, the Department of Health and Human Services, which is tasked with caring for unaccompanied migrant children, said it would use facilities at Fort Sill Army Base in Oklahoma to house minors. The base, which once held an internment camp for Japanese Americans, was used during the Obama administration for migrant children as well.

Ocasio-Cortez called the situation "a crisis" not just for those detained but also about whether "America will remain America in its actual principles and values or if we are losing to an authoritarian and fascist presidency."

"I don't use those words lightly. I don't use those words to just throw bombs. I use that word because that is what an administration that creates concentration camps is," she said. "A presidency that creates concentration camps is fascist, and it's very difficult to say that, because it is very difficult to accept the fact that that is how bad things have gotten, but that is how bad things have gotten."

The Department of Homeland Security has been overwhelmed by the sheer volume of migrants illegally crossing the southern border. The DHS found"dangerous overcrowding" and unsanitary conditionsat an El Paso, Texas, Border Patrol processing facility following an unannounced inspection in May. DHS said it "has implemented a multi-layered approach" that includes the construction of additional structures to house migrants, continued coordination with Immigration and Customs Enforcement and providing staff support.

Acting DHS Secretary Kevin McAleenan has urged Congress to provide additional funding to address the worsening situation at the border. The Senate Appropriations Committee is planning to mark up a border supplemental bill Wednesday in committee.

Ocasio-Cortez stood by her comments Tuesday, accusing Republican detractors of failing to understand the role of concentration camps.

"For the shrieking Republicans who don't know the difference: concentration camps are not the same as death camps," she tweeted Tuesday. "Concentration camps are considered by experts as 'the mass detention of civilians without trial.' And that's exactly what this administration is doing."

Rep. Liz Cheney, the No. 3 Republican in the House, accused Ocasio-Cortez of disrespecting the legacy of Jews killed during the Holocaust with her comments.

"Please @AOC do us all a favor and spend just a few minutes learning some actual history. 6 million Jews were exterminated in the Holocaust. You demean their memory and disgrace yourself with comments like this," the Wyoming Republican tweeted.

Ocasio-Cortez shot back, "Hey Rep. Cheney, since you're so eager to 'educate me,' I'm curious: What do YOU call building mass camps of people being detained without a trial? How would you dress up DHS's mass separation of thousands children at the border from their parents?"

Cheney replied that she is "happy to help educate" Ocasio-Cortez, and tweeted an Amazon link to Elie Wiesel's "Night," his book about his experiences during the Holocaust, urging her to read it.