A US Republican senator close to President Donald Trump has urged him to temporarily reopen the government for talks as Transportation Security Administration (TSA) staff absences closed an international airport concourse during the record 23-day shutdown.
Democrats have refused further negotiations until the government is reopened in a shutdown that became the US's longest in history over the weekend.
Republican senator Lindsey Graham, chairperson of the Senate Judiciary Committee, said he urged the president on Sunday to reopen the government for a limited period to try to get talks going again.
He said Mr Trump should, as threatened, declare a national emergency to seek funding for his border wall with Mexico if the reopening failed to sway the Democrats.
"Before he pulls the plug on the legislative option - and I think we are almost there - I would urge them to open up the government for a short period of time, like three weeks, before he pulls the plug, see if we can get a deal," Mr Graham said on Fox News Sunday.
However, he said Mr Trump told him, "let's make a deal, then open up the government".
That followed unscheduled absences among federal airport security screeners rising to 7.7 percent on Saturday - more than double the 3.2 percent rate of a year ago - as frozen pay cheques for staff at nine government agencies began to have a notable effect.
Miami International Airport closed its Concourse G for part of the weekend because of insufficient TSA staffing, although it said it expected to reopen on Monday.
The airport said it would reopen the concourse on Monday and "continue to monitor checkpoint staffing levels and make adjustments as necessary".
Screeners are among the lowest-paid federal employees. While they will be paid once the shutdown ends, many say they will struggle to pay bills in the meantime.
The record shutdown has furloughed 800,000 federal employees and cut government services across the US, caused by a lack of agreement between Republicans and Democrats over their funding.
It hinges on Mr Trump's demand that government funding include $5.7 billion of taxpayer money for a wall on the US border with Mexico, a key campaign promise. Democrats hold a majority in the house and refuse to include funding for the wall, while Mr Trump refuses to sign off the budget without it.
Mr Trump continued to blame Democrats for the impasse.
"I'm in the White House, waiting. The Democrats are everywhere but Washington as people await their pay. They are having fun and not even talking!", Mr Trump said on Sunday via Twitter.
Democratic House Speaker Nancy Pelosi's deputy chief of staff Drew Hammill responded on Twitter that "Speaker Pelosi has been in DC all weekend working from the Capitol."
Jennifer Lawless, a politics professor at the University of Virginia, said she believed Mr Trump and Republicans would lose the game of chicken as furloughed workers, travellers, tourists and others "experience the consequences of political dysfunction firsthand".
"The shutdown is real. The wall is hypothetical. And at some point soon, the Republicans are going to remember that it's real people in their districts who aren't getting paid, real people who aren't able to access government services, and real people who vote," she said.