The Donald Trump administration on Monday announced new rules that aim to deny permanent residency and citizenship to migrants who receive food stamps, Medicaid and other public welfare.

The new rules threatened to set back the citizenship hopes of millions of mostly Hispanic migrants who work for low wages and depend in part on public services to get by.

It also appeared to close the door for impoverished and low-skilled migrants outside the country hoping to legally obtain a foothold in the United States.

Announcing a new definition of the longstanding “public charge” law, the White House said migrants will be blocked from entering the country if they are likely to need public assistance. In addition, those already here and using public services will not be able to obtain green cards or US citizenship.

Under the new rule, a legal immigrant would be classified as a public charge if he or she receives one or more from a list of public benefits for a total of 12 months over a three-year period.

“To protect benefits for American citizens, immigrants must be financially self-sufficient,” Trump said in a White House statement.

“Large numbers of non-citizens and their families have taken advantage of our generous public benefits, limited resources that could otherwise go to vulnerable Americans,” the statement said.

The new order could impact some 22 million non-citizen legal residents of the country, and the estimated 10.5 million unauthorized immigrants, most of them-long-term residents.

The White House said that half of all non-citizen households include at least one person using Medicaid, the government-run health program.

It said that 78 per cent of households headed by a non-citizen with no more than a high school education use at least one welfare program.

“Through the public charge rule, President Trump’s administration is reinforcing the ideals of self-sufficiency and personal responsibility, ensuring that immigrants are able to support themselves and become successful here in America,” said Ken Cuccinelli, acting Director of US Citizenship and Immigration Services.

However, the plan has been slammed by immigrant and advocacy groups saying that it would undermine democracy and penalize parents for seeking help to feed their children.

“Basically, it is penalizing children, access to food for children of immigrant families with few resources,” Isaias Guerrero, an activist with the Fair Immigration Reform Movement (FIRM), told Efe news.

Cecilia Munoz, vice president for Public Interest Technology and Local Initiatives at New America, said the Trump administration was “using policy to eliminate the eligibility for many of those who typically obtain visas and are successful in the United States.”

“And that is because we have an administration that really wants to reduce immigration and is using every possibility to do so,” said Munoz, who served eight years as a senior adviser to Trump’s predecessor, Barack Obama.

The rule “sends the message that we don’t want immigrants,” said Carlos Gutierrez, who was commerce secretary under former President George W Bush.

“It’s an anti-immigrant policy, it’s a policy against people who are different. I think they want blonds, I don’t know,” Gutierrez said. “But we see that this is an administration that doesn’t like immigrants and that’s going to be a problem. I don’t know where it will stop.”

Andrew Selee, president of the non-partisan Migration Policy Institute (MPI), said that policies toward immigrants will have an impact on the future of the US economy.

“This country has always benefited from the flow of people from all over the world. It’s a central part of the innovation, of the economic dynamism of this country, of the labour force,” he said.

(With agency inputs)