President Donald Trump has threatened to veto any immigration legislation that does not mirror his own proposal to dramatically reshape the US’s immigration system and build a border wall. 

In the midst of a Senate immigration debate over a measure to protect young undocumented immigrants – so-called dreamers – Mr Trump threw his support behind a Republican bill that he says incorporates his four principles outlined in a White House framework for any immigration bill.

“I am asking all senators, in both parties, to support the Grassley bill and to oppose any legislation that fails to fulfill these four pillars – that includes opposing any short-term ‘Band-Aid’ approach,” Mr Trump said in a statement. 

According to the White House framework, Mr Trump would grant about 1.8m dreamers legal status, including a path to citizenship – in exchange for increased immigration enforcement, the construction of his long-promised border wall, and a restructuring of legal immigration channels that moves away from reuniting families and gives priority to higher-skilled immigrants.

Mr Trump essentially forced Congress to address US immigration policy, a big talking point during his presidential campaign, when he rescinded the Deferred Action for Childhood Arrivals programme in September. The Obama-era policy lets young immigrants who were brought to the US illegally as minors live and work in the US without fear of deportation.

Mr Trump said legislation that does not include his priorities will not – in his own words –  “deliver safety, security and prosperity to the American People.” 

Republican Senator Chuck Grassley’s legislation, which is being co-sponsored by five other Republicans, would offer a chance for citizenship for up to 1.8m dreamers. It would also provide $25 billion for border security, restrict family-based immigration and end a visa lottery.

The National Immigration Law Center called it “a copied and pasted version of President Trump’s #DACA ransom.”

“It’s not a serious proposal to #ProtectDreamers and only caters to one audience – anti-immigrant restrictionists,” the organisation wrote on Twitter. “Anything that resembles this bill should be rejected immediately.” 

On Wednesday, the White House said the President would not support the bipartisan McCain-Coons proposal, from Republican Senator John McCain and Democratic Senator Coons. 

White House spokeswoman Lindsay Walters said the plan “would increase illegal immigration, surge chain migration, continue catch and release, and give a pathway to citizenship to convicted alien felons.” 

The Department of Homeland Security also slammed the measure for not putting “a single penny” toward border security. 

“The McCain-Coons proposal does not authorise a single penny for appropriations for border security, ensuring that our nation’s border is never secured or our national security protected,” DHS said in a statement. “Rather than securing our border, the McCain-Coons proposal requires DHS to submit a strategy on border security Congress – something that DHS has already done.”

The measured proposed by Mr McCain and Mr Coons would give a pathway to citizenship for 3.2m illegal immigrants and authorise only $3 billion of the $25 billion President Trump had requested for border security.

The clock is ticking as senators search for an agreement that will receive the 60 votes needed for the bill to clear the chamber. They have less than three weeks to go until DACA expires, and any measure approved by the Senate would also need to be approved by the more conservative House of Representatives.

Immigration has been a troublesome issue for Congress, with former President Barack Obama having implemented DACA only after a lack of congressional action on immigration reform.

With less than three days to go before the Senate’s immigration debate is expected to end, Democratic Senator Dick Durbin, one of the key immigration negotiators, is pulling out all the stops to oppose parts of Mr Trump’s framework. 

Mr Durbin on the Senate floor told the story of US Olympian Chloe Kim, who has won a gold medal in snowboarding during the 2018 Winter Olympic Games in South Korea. 

Mr Durbin said the 17-year-old’s family would not have been allowed to come to US under policies endorsed by the President.