WASHINGTON, United States (AFP) — US President Donald Trump on Wednesday threw his weight behind efforts to give English-speakers priority for US residency cards and halving the number of legal migrants admitted to the country.

Trump backed proposals that would reform the process of obtaining a US “green card” by introducing a points-based system favouring skilled Anglophone workers.

Around one million immigrants are granted permanent residency each year, but the draft legislation — presented at the White House by Trump and two senators who crafted it — aims to cut that number by around 50 per cent.

It would also put a cap on the number of refugees able to gain permanent residency at 50,000 a year.

Trump hailed what he described as “the most significant reform to our immigration system in half a century.”

The legislation has only a slim chance of passing in Congress, but gives the White House an opportunity to show Trump’s base supporters that he is trying to live up to his hardline promises.

Standing in the Roosevelt Room flanked by Senators Tom Cotton and David Perdue, Trump said that the United States had admitted too many low-skilled workers and claimed they were taking jobs from Americans.

“This policy has placed pressure on American workers, taxpayers and community resources,” he said. “It has not been fair to our people, to our citizens, to our workers.”

He pointed to the benefits of a Canadian- or Australian-style points-based system.

“This competitive application process will favour applicants who can speak English, financially support themselves and their families, and demonstrate skills that will contribute to our economy,” he said.

Trump said the new system, if approved, would “help ensure that newcomers to our wonderful country will be assimilated, will succeed and achieve the American dream,” while also protecting “struggling American families.”

Critics say that the proposals would actually result in falling wages, by slashing the number of migrants creating jobs.

The National Academy of Sciences studied two decades of data and found the impact of immigration on the wages of American-born workers to be “very small.”

The academy also concluded that “immigration has an overall positive impact on long-run economic growth in the US,” although first-generation immigrants do place more of a burden on state resources.

But Trump’s message is likely to resonate strongly with low-skilled white workers who have seen wages stagnate and believe their long-held cultural dominance is being eroded.

Trump has made tackling illegal immigration from Latin America a key plank of his politics.

He has promised to build a “wall” on America’s southern border with Mexico and tackle violent Hispanic gangs at home.

But the effort to curb legal immigration is unlikely to be universally welcomed by business leaders or within the Republican Party.

Cotton first introduced the proposals in February to the Senate, where they have been stalled ever since.