US Senate Republicans Abandon Immigration Bill Amid Internal Disagreements

US Senate Republicans have abandoned plans to advance major immigration enforcement legislation after furious internal disagreement over a proposed compensation fund for Trump allies who claim they were unfairly targeted by federal agencies.

The collapse was a significant setback for US President Donald Trump and party leaders, who had hoped to pass roughly $US70 billion ($98 billion) in funding for Immigration and Customs Enforcement (ICE), Border Patrol and other agencies before members of Congress began a week-long recess.

Instead, the debate exposed rare public resistance from Republicans normally inclined to fall in line behind the US president, with senators baulking at provisions they feared would be politically toxic in an election year dominated by affordability concerns.

The immediate flashpoint was Mr Trump's proposed "anti-weaponisation fund", which critics warned could send taxpayer money to his supporters convicted of violence against police officers during the 2021 attack on the US Capitol.

"Senate Republicans couldn't even hold their own conference together long enough to bring this partisan bill to the floor before recess," Democratic senators Mark Warner and Tim Kaine said in a joint statement.

"After weeks of rushing ahead with backroom negotiations, Republicans are now openly fighting amongst themselves over a bill that would pour billions more into President Trump's extreme immigration agenda and green-light nearly $US1.8 billion [$2.5 billion] in taxpayer money for a slush fund to reward Trump's political allies."

The decision meant senators were leaving Washington without passing the immigration package, blowing past Mr Trump's June 1 deadline for approving a major pillar of his domestic agenda.

Acting Attorney-General Todd Blanche met privately with Republican senators just before the negotiations collapsed in an effort to calm concerns over the fund, but several emerged unconvinced.

Republicans had also been divided over a separate proposal for up to $US1 billion ($1.4 billion) in Secret Service funding tied to security for Mr Trump's planned White House ballroom.

Senate leaders had already concluded that the ballroom funding would have to be dropped from the text because of insufficient support and procedural obstacles.

The double retreat underscored growing unease among Republicans over Trump priorities that Democrats have cast as evidence of a president more focused on personal projects and political grievances than on the cost of living.

Mr Trump had dismissed the potential ballroom rebellion, telling reporters he was relying on private donations for the project and did not need the public money anyway.

Democrats had been preparing to force repeated votes on both the ballroom and compensation fund, hoping to portray Republicans as defending money for rioters and a vanity project while families struggled with mortgages, groceries and gasoline.

The setback comes as Mr Trump's campaign of retribution against Republicans who cross him has stirred frustration inside the party, emboldening rebels to oppose the president like almost never before.

Mr Trump helped defeat Senator Bill Cassidy in Louisiana, pushed to oust Kentucky Representative Thomas Massie and endorsed Texas Attorney-General Ken Paxton over longtime senator John Cornyn in a run-off next week.

Several Republican senators have warned that those vendettas could make it harder to pass Mr Trump's agenda by alienating those whose votes he still needs.

Senate Majority Leader John Thune has acknowledged that Mr Trump's interventions in primaries can make moving legislation "slightly more complicated".

That tension is now playing out in real time, as Republicans remain eager to deliver Mr Trump a major immigration victory but are proving far less willing to defend every politically explosive demand that comes with it.

"The American people will see it in black and white. Our contrast will be glaringly clear," Top Senate Democrat Chuck Schumer told reporters before the negotiations collapsed.

"Ballroom Republicans are not working for you. They're busy fighting for Trump. Democrats are fighting for you."