WASHINGTON - US President Donald Trump said on Tuesday he would "love" to see another government shutdown as Republicans and Democrats in Congress worked to reach a budget deal that would prevent federal agencies from having to close their doors this week.

As lawmakers in Congress closed in on a bipartisan budget deal that could end months of budget uncertainty, Trump threatened to upend the discussions by insisting that any spending package would have to include changes to immigration laws - the very issue that led to a three-day shutdown last month.

"I'd love to see a shutdown if we don't get this stuff taken care of," he said at the White House.

The White House later clarified that it did not expect the budget deal to include specifics on immigration.

Republican and Democratic leaders in the Senate say they are close to an agreement that could dramatically raise spending levels for both military and domestic programs and ensure that the government will keep operating when temporary spending expires on Thursday.

The deal could potentially put an end to the brinkmanship over spending that has periodically roiled Washington and that resulted in funds running out for the government in January.

"I'm optimistic that very soon we'll be able to reach an agreement," Senate Republican Leader Mitch McConnell told reporters.

Senate Democratic Leader Chuck Schumer said the agreement would include an increase for domestic programs like drug treatment and broadband infrastructure that Democrats have sought, as well as a military spending increase championed by Republicans.

"We're making real progress on a spending deal," he told reporters.

January's shutdown came about after Democrats insisted that any spending bill must also include protections for young immigrants who were brought to the country illegally as children, who are known as "Dreamers".

Democrats are not taking that approach this time around.

"Nobody wants another one but him," Schumer said.

Trump's fellow Republicans, who control both chambers of Congress, are also eager to keep spending and immigration separate.

"We don't need a government shutdown on this," Republican Representative Barbara Comstock told Trump at the White House.

The potential budget deal in the Senate could head off another round of the last-minute posturing that preceded last month's shutdown.

The Republican-led House of Representatives was set to vote on Tuesday evening on a stopgap spending bill.

Reuters