US President Donald Trump announced sweeping plans to crack down on immigration, saying current policy has eroded national progress and that he would “permanently pause migration from all Third World Countries to allow the US system to fully recover.”

In a pair of Truth Social posts late Thursday night in Washington, Trump said he would terminate “millions” of admissions under his predecessor Joe Biden, “remove anyone who is not a net asset to the United States, or is incapable of loving our Country” and “denaturalie migrants who undermine domestic tranquility.” He added that he would “end all Federal benefitis and subsidies” to noncitizens.

“These goals will be pursued with the aim of achieving a major reduction in illegal and disruptive populations, including those admitted through an unauthorized and illegal Autopen approval process,” Trump said. “Only REVERSE MIGRATION can fully cure this situation.”

The post didn’t include specifics on what the president considered a “third world” country, an ill-defined term typically used to refer to poorer nations. It followed an attack on two National Guard members in the capital earlier by an Afghan national. Earlier in the day, the president had announced the death of one of the guardsman, US Army Specialist Sarah Beckstrom, 20.

Trump has used the assault to amplify his administration’s anti-immigration policies. The White House had already expanded its immigration crackdown in the aftermath of the shooting, including halting reviews of Afghan immigration proceedings and ordering a review of those already in the US. The Trump administration also plans to review the cases of all refugees resettled under Biden and freeze their green card applications, according to a memo earlier this month reviewed by Bloomberg.

On Thursday, Joseph Edlow, the head of US Citizenship and Immigration Services, said in a social media post that his agency, under Trump’s orders, is conducting “a full scale, rigorous reexamination of every Green Card for every alien from every country of concern.” The White House in June had flagged 19 countries, including Afghanistan, Haiti, Somalia and Sudan, for immigration restrictions.