WASHINGTON – President Donald Trump took another step Thursday to crack down on legal immigration, instructing agencies to enforce a 23-year-old law that requires sponsors of green card holders to reimburse the government for welfare benefits.

Trump approved a memorandum Thursday to enforce a pair of provisions signed into law by President Bill Clinton in 1996, the White House said. The move comes as Trump has sought to overhaul legal immigration despite congressional resistance.

"To protect benefits for American citizens, immigrants must be financially self-sufficient," Trump said in an announcement of the plan.

Critics have said that such moves unfairly punish low-income immigrants, who sometimes need assistance to get started in the U.S. But the White House counters that too many immigrants take advantage of U.S. generosity, pointing out that 58% of all households headed by a non-citizen use at least one welfare program.

Immigration advocates Marielena Hincapié, executive director of the National Immigration Law Center, and Olivia Golden, executive director of the Center for Law and Social Policy, denounced Trump's "brutal, reckless, dangerous, inhumane agenda."

“Trump will do anything to send immigrant families the message that if you’re not white and wealthy, you’re not welcome — or even safe — here," the two advocates, who are also co-chairs of the Protecting Immigrant Families Campaign, said in a statement. "And he doesn’t care that children and entire families will be harmed in the process."

Administration officials announced last year they were enforcing a law requiring immigrants to "show they can support themselves financially." More than 6 in 10 green cards are granted based on family ties, Department of Homeland Security data show.

Legal immigrants:Trump immigration plan sidesteps immigrants here illegally

Who pays? How Trump administration plans to screen green card applicants

White House officials did not respond to a request for comment. The White House did not provide the actual memorandum, only a fact sheet outlining its provisions. It was not immediately clear how many people would be affected by the order.

The U.S. grants green cards to roughly 1 million foreigners each year.

Thursday’s move is just the latest in the administration’s efforts to limit what public benefits legal and undocumented immigrants can receive.

In October, the Department of Homeland Security proposed new guidelines to redefine whether would-be immigrants are considered a "public charge," rendering them ineligible to become legal permanent residents.

The current definition defines a public charge as someone who is "primarily dependent" on government assistance. That means receiving cash assistance that makes up more than half of their income, or receiving long-term medical care "at government expense."

The new definition, which has not yet gone into effect, would dramatically expand that definition to include any immigrant who receives even small amounts of government aid. That includes "non-cash" benefits, such as use of the Supplemental Nutrition Assistance Program (known as food stamps), Medicare Part D prescription drug benefits, Medicaid in non-emergency situations, and Section 8 housing and rental assistance.

The attempt to limit housing assistance flared up in Congress this week when Housing and Urban Development Secretary Ben Carson appeared before a House committee to defend his agency’s plans to evict undocumented immigrants – and their U.S.-born children – from subsidized housing. Carson defended the plan by saying the U.S. needs to “take care of (our) own first.”

"It's not that we’re cruel, mean-hearted. It’s that we are logical," Carson said.

Like what you’re reading? Download the USA TODAY app for more