Image copyright EPA

President Donald Trump has backed an immigration overhaul that would reduce the number of permanent, legal migrants allowed in the US each year.

He joins Republican Senators Tom Cotton and David Perdue, who in February proposed a bill to cut legal immigration by 50% over 10 years.

The Raise Act would end diversity lottery visas and curb the number of refugees offered permanent residency.

Immigration reform was a centrepiece of Mr Trump's presidential campaign.

Media playback is unsupported on your device Media caption Stephen Miller called Jim Acosta's statement "insulting, ignorant and foolish"

But the bill has a long way to go before becoming law and would be likely to face resistance in Congress from members of both parties.

Republican Senator Lindsey Graham said that the bill would have a "devastating" impact on the economy in South Carolina - the state he represents.

'Pro-American immigration reform'

Joined by Senators Cotton and Perdue at the White House on Wednesday, Mr Trump framed the plan as "the most significant reform to our immigration system in half a century".

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

The proposal would reduce the number of refugees admitted each year to 50,000 from the 110,000 that former President Barack Obama said he would welcome last year.

The bill also would eliminate the State Department's Diversity Immigrant Visa Program, a lottery programme that allows about 50,000 people to live in the US permanently each year.

Image copyright Reuters Image caption The original ban in January provoked protests at US airports

An estimated 1,051,031 immigrants were granted permanent residence in the US in 2015, according to the Department of Homeland Security.

The proposal would also no longer give green card preference to the extended family or adult children of immigrants who already live legally in the US.

During a fiery daily news briefing, White House senior adviser Stephen Miller said they were also proposing to limit family-based migration to spouses and children.

He said the administration planned to introduce an Australian-style, points-based immigration system.

Mr Miller described the policy as "pro-American immigration reform" that enjoyed "immense" support among the public.

He was asked whether the Trump Organization would stop hiring foreign workers to set an example for the rest of the country.

Mr Miller replied: "This bill, of course, doesn't deal with guest workers and temporary non-immigrant visas."

Mr Trump has long vowed to crack down on the US immigration system.

He launched his presidential campaign on the promise of building a wall along the US-Mexican border to halt illegal immigration and drug trafficking.

Media playback is unsupported on your device Media caption The impact of the wall on wildlife: Victoria Gill joins scientists working in the Sonoran Desert

The Trump administration marked a victory in June, when the US Supreme Court partially restored the president's controversial executive order temporarily restricting travel from six mainly Muslim countries and freezing the refugee programme.

The order had previously been blocked by lower courts since February.