WASHINGTON (Reuters) - The White House said on Tuesday it was searching for ways to unilaterally fund the building of a controversial wall on the U.S.-Mexico border that Congress is balking at, possibly easing chances of a government shutdown this weekend.

White House Press Secretary Sarah Sanders told reporters President Donald Trump has asked his Cabinet agencies to “look and see if they have money that can be used” to begin building the wall.

Previously, Trump had demanded that Congress approve $5 billion in new funds for the wall that he argues is needed to stop illegal immigrants and drugs from entering through the southwest border.

On Tuesday, Trump said it was too early to say whether a partial government shutdown will be averted by a Friday midnight deadline when existing funds for several agencies expire. “We’ll see what happens,” he told reporters.

But some Republican senators said they thought the president could be persuaded to sign a bill that does not fund his wall, and several Republican and Democratic senators spoke of the possibility of a stop-gap funding bill passing this week that would simply extend government operations into the new year.

The new Congress that convenes on Jan. 3 would then have to grapple with the budget impasse.

Given the continued uncertainty, however, federal agencies began publicizing their plans in case of a partial government shutdown.

The State Department, for example, said its consular operations, both domestic and abroad, would continue “as long as there are sufficient fees to support operations.” However, passport agencies might not operate if they are located in government buildings affected by the lapse in appropriations.

Earlier on Tuesday, Trump and Senate Majority Leader Mitch McConnell had proposed a plan that would have had Congress approve $1 billion in unspecified money that Trump could use to advance his border security priorities.

Senate Democratic Leader Chuck Schumer called it a “slush fund” that was promptly rejected.

Democrats, along with some Republicans, oppose the wall as a costly, ineffective border security tool.

Even some Republicans balked at the $1 billion fund. “I’m not sure I would insist on that,” Senator Roger Wicker told reporters.

Republican Senator Marco Rubio, referring to the prospects of a bill to extend current spending for a short period, such as a few weeks “might be the only route forward considering the time constraints we face.” Schumer said Democrats would “very seriously consider” such a move.

FILE PHOTO: Workers on the U.S. side, work on the border wall between Mexico and the U.S., as seen from Tijuana, Mexico, December 13, 2018. REUTERS/Carlos Garcia Rawlins

Congress has been trying to approve around $450 billion in funds to keep a variety of federal agencies operating beyond Friday. Included is the Department of Homeland Security, which is responsible for border security.

Failure to agree to new appropriations by that deadline could leave about a quarter of the federal workforce without paychecks and some federal programs shuttered until the impasse is resolved.

Trump has demanded $5 billion as a down payment on construction of a wall, which was a key pledge of his 2016 presidential campaign. Trump originally said Mexico would pay for the wall, but Mexico has refused.

It was unclear whether any Cabinet heads, such as Defense Secretary James Mattis, would find money in their existing accounts to funnel to a wall, or whether they even had the authority to do so.