Congressional Republicans say they have reached a deal to end the partial US government shutdown - the longest in history - as early as this week.

The plan would fund most of the Department of Homeland Security (DHS) through one spending package, and Immigration and Customs Enforcement (ICE) and Customs and Border Protection (CBP) through a separate budget.

After days of infighting, Republican House Speaker Mike Johnson and Senate Majority Leader John Thune jointly confirmed the deal. Top Democrat Chuck Schumer said Republicans had "caved".

The impasse has spawned chaos at US airports due to a shortage of Transportation Security Administration (TSA) officers at security checkpoints.

Johnson and Thune said in their joint statement that lawmakers in their party, which holds narrow majorities in both chambers, will "in the coming days" follow through on President Donald Trump's directive to fully fund DHS using two parallel tracks.

"We appreciate and share the President's determination to once and for all bring an end to the Democrat DHS shutdown," they said.

Lawmakers have been working for weeks to reach a deal that would win over enough Democrats to pass both the House and the Senate and go to Trump to sign into law.

Democrats have demanded reforms to immigration enforcement in exchange for signing off on funding for ICE, after two Americans were killed protesting immigration operations in Minnesota. That has put funds for the entire department, which also includes security agents at airports, into limbo.

The agreement comes after House Republicans - and Trump - rejected a funding plan unanimously adopted by the Senate last week.

That bipartisan compromise would have partially funded DHS, while excluding ICE. But Republicans in the House instead voted to approve a short-term measure that would have funded the department in its entirety.

Trump demanded in a social media post earlier on Wednesday that Republicans bring him a bill to fund border patrol and ICE agents by 1 June. He said the plan should include a process that bypasses a filibuster, allowing Democrats to stall or kill the bill.

A White House official told the BBC on Wednesday that it was supportive of Johnson and Thune's approach.

With lawmakers locked in their standoff, DHS has not received any new funds since 14 February.

While ICE was able to pay its agents using money from Trump's massive tax and spending bill passed last year, another part of DHS, the TSA, could not pay workers.

Hundreds of TSA officers quit, and thousands of others did not show up to work, leaving them without pay, leading to long lines at airports for security screenings.

TSA agents started receiving pay again this week after Trump ordered his administration to find a way to fund the airport security workers.