Donald Trump was set to be the first U.S. president to attend the World Economic Forum in Davos, Switzerland, in nearly two decades, but the government shutdown might have scrambled those plans.

White House budget chief Mick Mulvaney said Saturday that Trump's plans to travel to Davos next week are up in the air while Congress scrambles to strike a deal to fund the federal government.

"We're taking Davos, from the president's perspective and the Cabinet's perspective, on a day-by-day basis," Mulvaney told reporters during an impromptu briefing.

The government shut down at midnight Friday, after congressional negotiators failed to pass a budget. Earlier in the day, Trump cancelled a planned trip to Florida, where he was scheduled to host a party at his private Mar-a-Lago club to mark the one year anniversary of his inauguration.

Tickets for the Mar-a-Lago party begin at $100,000 per couple, and proceeds will benefit the Trump reelection campaign and the Republican National Committee. On Saturday, RNC staffers were busy setting up TV screens in the private club, so Trump could address the guests via satellite, according to CNN.

The budget impasse showed no signs of letting up on Saturday, as both Democrats and Republicans dug their heels in, and each party blamed the other.

The president is scheduled to depart for Switzerland on Wednesday, along with a delegation of more than a dozen Cabinet members, including Treasury Secretary Steven Mnuchin, and top White House aides.

In 2000, Bill Clinton was the first and, for now, last sitting U.S. president to attend the World Economic Forum. Neither George W. Bush nor Barack Obama attended during their terms, while Ronald Reagan appeared via video link.