US President Donald Trump and Republican lawmakers took a tough stance on Saturday after Congress failed to fund federal agencies, saying they would not negotiate on immigration until Democrats help end the government shutdown.
Funding for federal agencies ran out at midnight with no agreement in Congress, meaning the second year of Mr Trump's presidency began without a fully functioning government. Lawmakers failed to resolve an impasse over Democrats' demands that any short-term spending legislation include protections for young undocumented immigrants.
US government workers were told to stay home or, in some cases, work without pay until new funding is approved in the first federal government shutdown since a 16-day funding lapse in October 2013.
A trip by Mr Trump and some Cabinet members to the World Economic Forum in Davos, Switzerland, was in flux, White House budget director Mick Mulvaney said, with the situation being assessed on a day-to-day basis.
Parks, open-air monuments and Smithsonian museums were open in the US capital as a women's rights march took place on the National Mall. But visitors were turned away from the Liberty Bell in Philadelphia and the Statue of Liberty in New York Harbor.
Speaking at the US Capitol, Senate Democratic Leader Chuck Schumer delivered a stinging portrayal of Mr Trump as an unreliable negotiating partner, saying the two sides came close to an agreement several times only to have Mr Trump back out at the urging of anti-immigration conservatives.
"Negotiating with Mr Trump is like negotiating with Jell-O," said Mr Schumer, who met Mr Trump at the White House on Friday for a 90-minute meeting that had briefly raised hopes. "It's impossible to negotiate with a constantly moving target."
The Republican-controlled Senate and House of Representatives held rare weekend sessions on Saturday, facing a political crisis that could have an impact on congressional elections in November.
Both Republicans and Democrats dug in, with each side blaming the other. Republicans said they would refuse to negotiate on immigration until Democrats provide the votes to re-open the government. Democrats insisted they have been willing to compromise but Republicans backed out of deals.
"The President will not negotiate on immigration reform until Democrats stop playing games and reopen the government," said White House spokeswoman Sarah Sanders.
Marc Short, the White House's legislative affairs director, said Mr Trump had been in contact with Republican leaders in Congress during the day, but had not reached out to Democrats.
Mr Short said the President likely would be most effective making the case for ending the shutdown directly to the American people, and he did not rule out Mr Trump addressing the nation in the coming days.
The tough message from the White House and Republicans in Congress led to speculation that Washington could be in for a prolonged political battle.
The shutdown began a year to the day after Mr Trump was sworn in as president. He portrayed himself as the ultimate dealmaker, but his inability to cut a deal despite having a Republican majority in both houses of Congress marked arguably the most debilitating setback for his administration.
"This is the One Year Anniversary of my Presidency and the Democrats wanted to give me a nice present," he said on Twitter.
"Democrats are far more concerned with illegal immigrants than they are with our great military or safety at our dangerous southern border," he said. "They could have easily made a deal but decided to play shutdown politics instead."