A cloud of teargas fired by U.S. Customs and Border Protection after migrants from Central America attempted to illegally cross the border into the United States. (Adrees Latif/Reuters)

Kirstjen Nielsen, the homeland security secretary, on Monday joined President Trump in defending the use of tear gas against migrants seeking to enter the United States to seek asylum. She went so far as to thank Trump for his combat-ready posture at the border, heaping praise on the president as he reportedly prepares to remove her from her position at the helm of immigration enforcement.

The embattled Cabinet secretary also sought to fend off criticism of the severe tactics taken Sunday against women and children who appeared in searing photos from the border by suggesting without evidence that they were being used as “human shields.”

“It appears in some cases that the limited number of women and children in the caravan are being used by the organizers as ‘human shields’ when they confront law enforcement,” she said in a statement. “They are being put at risk by the caravan organizers as we saw at the Mexico-Guatemala border. This is putting vulnerable people in harms way.”

The assertion matched one offered by Trump on Monday evening, when he labeled these migrants “grabbers.”

“They feel they have an advantage when they’re with a young child, and they call them grabbers,” the president told reporters. “That’s a term I’ve heard, but that’s what they call them, grabbers. They grab a child because when they have a child they feel a lot safer.”

Nielsen suggested that border agents had to use tear gas after migrants began throwing “rocks and projectiles” at them. Authorities, she said, were entitled to “self-defense” and had “responded admirably and responsibly to the events on Sunday.” She said it was a “testament to their training and professionalism that no one was injured.”

International treaties bar the use of tear gas and other chemical weapons in warfare. But domestic use is not prohibited, and the substance, formally known as a lachrymator agent, is sometimes used in drills and for riot control.

“The accepted use of nonlethal force (also used by the Obama Administration in 2013) prevented further injury to agents and a mass illegal rush across the border,” Nielsen said.

The statement referred to an incident in President Barack Obama’s second term in which border agents used pepper spray against migrants who were throwing rocks and bottles at them, as the San Diego Union-Tribune reported at the time. Both incidents unfolded at the San Ysidro border crossing. The episode from five years ago has been seized on by conservative media, including Fox News, to defend the use of tear gas against asylum seekers, which drew condemnation from Democrats, activists and legal advocates.

Nielsen’s response to the public outcry hardly assuaged these concerns.

The ACLU, in a statement to The Washington Post, said the justification of maneuvers on the border “relies mainly on misdirection and repeatedly makes unsupportable, illogical leaps.” The civil liberties organization, which has sparred in court with the administration over its stringent immigration policies, accused the Cabinet secretary of “running her department as an instrument of President Trump’s anti-immigrant agenda.” The ACLU called on Congress to respond by withholding funding from the Department of Homeland Security.

Nielsen also claimed the migrants were “predominately male” after images circulated Sunday on social media showing young children contorting themselves to escape the tear gas. She said the “overwhelming majority” of their asylum claims were without merit, given the historically low success rate of asylum seekers from Guatemala, Honduras and El Salvador. But nowhere does likelihood of success figure into eligibility requirements for sanctuary, which require migrants to be fleeing persecution in their home countries.

The ACLU, in its statement, said that Nielsen had erred most grievously in suggesting “that it is okay to forgo a meaningful asylum process simply because some people may not ultimately obtain asylum. That is neither legal nor fair.”

Nielsen has been the face of President Trump’s hard-line immigration policy, including his administration’s decision to separate migrant children from their parents.

“Secretary Nielsen’s defense of these actions is to be expected from a leader who has overseen the separation of families and the enforcement of a racist immigration policy that’s rapidly expanded the detention of a record-breaking number of immigrants,” said Jonathan Ryan, executive director of the Texas-based nonprofit Refugee and Immigrant Center for Education and Legal Services, or RAICES. “Yesterday [U.S. Customs and Border Protection] officers attacked children carrying their strollers with rubber bullets and tear gas. This is outrageous and wrong on so many levels.”

But Nielsen dismissed these events, which were captured on camera, as “rumors” and “misinformation.” She said members of the caravan — “far larger and more organized than previous ones” — were to blame for the violence, which she described as “entirely predictable.” She said authorities would be ready for the “next assault.”

“We predicted the violence we saw on Sunday,” she said, blaming Congress for the flare-up — which has also been the president’s stock response. Trump’s contention that congressional Democrats are responsible for the excesses of his own immigration policy because they don’t get in line with his priorities, including funding of the border wall, misunderstands the separation of powers.

Nielsen praised Trump for deploying active-duty troops to the border, pointedly denying that the move represented a “political stunt.” The deployment was announced in the lead-up to this month’s midterm election, in which the president made nativism and xenophobia the GOP’s closing argument.

While authorities could not confirm the backgrounds and identities of all caravan members, she acknowledged, “we have confirmed that there are over 600 convicted criminals traveling with the caravan flow,” Nielsen said. Yet her description of furtive criminals penetrating the border was at odds with images of unarmed civilians gathered in crowds awash with strollers.

Trump on Monday painted a similarly forbidding portrait of the Central American migrants, praising border authorities and saying they “had to use” tear gas because “they were being rushed by some very tough people.”

The assessments of his own administration don’t entirely bear his argument out.

In a report this year, the Drug Enforcement Administration said drug-related crimes in Mexico, even as they “reach epidemic proportions,” result in “little spillover violence in the United States.” Violence associated with what the agency terms “Transnational Criminal Organizations” is “less frequent” north of the border and primarily linked to trafficker-on-trafficker disputes.

Fred Barbash contributed to this report.