The White House set the tone early when Press Secretary Sarah Huckabee Sanders indicated Trump - who just last week said he'd be "proud" to shut down the government - doesn't want to after all.

The president would consider other options and the administration was looking at ways to find the funding elsewhere, Sanders said.

"The president has asked every agency to look and see if they have money that can be used," Sanders said.

It was a turnaround after days of impasse. Without a resolution, more than 800,000 government workers could be furloughed or sent to work without pay, disrupting government operations days before Christmas.

One option that has been circulating on Capitol Hill would be to simply approve government funding at existing levels, without a boost for the border, as a stopgap measure to kick the issue into the new Congress next year. The White House preference was for such a short-term package, said a person familiar with the negotiations.

"We want to know what can pass," Sanders said at a press briefing. "Once they make a decision and they put something on the table, we'll make a determination on whether we'll move forward."

The turn of events kick-started negotiations that had been almost nonexistent since last week's televised meeting at the White House, when Trump neither accepted nor rejected the Democrats' offer.

They had proposed keeping funding at current levels of $US1.3 billion ($A1.8 billion) for border security fencing and other improvements, but not for the wall.

The Senate's top Republican and Democratic leaders began negotiating new proposals and talks were expected to continue.

Senate Majority Leader Mitch McConnell said he was confident there would not be a government shutdown on Friday when funding for parts of the government expires.

McConnell said a stopgap measure could be approved, though he suggested Nancy Pelosi, who is poised to become House speaker when the Democrats take control January 3, would not want to saddle the new year with a budget brawl.

"If I were in her shoes, I would rather not be dealing with this year's business next year," McConnell said.

Pelosi and Senate Minority Leader Chuck Schumer have made it clear they are not interested in funding Trump's border wall.

Democrats also rejected the administration's idea of shifting money from other accounts to pay for the wall.

The White House showed its willingness to budge as it became apparent the president does not have support in Congress for funding the wall at the $US5 billion ($A7.0 billion) level he wants.

Sanders said there are "other ways" to secure the funding.

"At the end of the day, we don't want to shut down the government," Sanders said on Fox News Channel.

"We want to shut down the border from illegal immigration."

Australian Associated Press