Hundreds of frustrated travelers were stuck on snaking lines inside the Delta Airlines terminal at LaGuardia Airport in New York City Sunday afternoon, as a handful of airport employees tried to keep them calm.
James Gregory, the TSA's deputy assistant administrator of public affairs, said the agency is "not seeing any significant increases in average wait times or callouts." He added that the long lines were a "normal occurrence" at this time of the year.
"It's also worth reporting that we are grateful for the more than 51,000 agents across the country who show up to work, remain focused on the mission and are respectful to the traveling public as they continue the important work necessary to secure the nation’s transportation systems," he said.
Regardless of the cause, airport employees had their hands full trying to manage the endless lines.
"Please, everyone, have patience with the officers who came to work," a Delta Airlines employee pleaded with travelers surrounding her. "Please."
The airline declined to comment about the delays but passengers said the situation at LaGuardia, which is under a massive rebuilding construction project already, had reached a new low.
"I’ve never seen the line in LaGuardia that bad," said John, a frequent business traveler who asked that his last name not be used. "And I probably take the shuttle 40 to 50 times each year, 25 round trips.”
The government shutdown, which has left roughly 800,000 federal employees without pay, has affected a wide range of professionals, from members of the Coast Guard to air traffic controllers.
Negotiations between congressional Democrats and the Trump administration to reopen the government have stalled over the president's demands for border wall funding. This Friday, Jan. 11, is the first scheduled payday that will be missed for federal employees in affected roles since the shutdown began.
Michael Bilello, TSA's assistant administrator for strategic communications and public affairs, said staffing levels at Dallas/Fort Worth International Airport were slightly down.
On Friday, the callout rate was 5.5 percent of workers, compared to 3.5 percent on a "normal" day, Bilello said.
When asked by ABC News what the slight increase can be attributed to, he said it "could be anything."
"Could be transportation, kids are home from school for the holidays," he added. "But, you know, there probably are some folks in there that perhaps are not coming in because they’re frustrated or because they’re looking for other jobs.
"That's the reality of it," he continued. "But, I don’t see anything that shows that it’s coordinated or that its certainly having any impact on operations to date."
Still, wait times at the airport never exceeded 25 minutes, he added, precheck travelers never waited longer than 8 minutes. Of all of the travelers at TSA checkpoints Friday, more than 90 percent of them waited less than 15 minutes, he said.
On Thursday and Friday, more than 4 million travelers nationwide were screened, Bilello said. The vast majority -- in the 90th percentile -- didn't have to wait more than 15 minutes, he said.
At other airports in big cities like Houston and Chicago, delay times seemed to be normal. And Bilello disputed reports that more than 150 TSA agents called out sick at JFK International Airport in New York.
Bilello also attributed the delays to normal slowness at the end of the holiday season.
"While call outs have increased nationwide, right around this time of year, right around Christmas that’s not unusual," Bilello said. "These numbers are certainly not extraordinary."
Nevertheless, some flyers ABC News spoke with seemed to be factoring in the shutdown and the threat of TSA agents calling out sick into their travel plans.
Debbie Jacob, who was flying to Rochester with her mother and daughter, told ABC News she came to the airport "several hours earlier than our flight was to depart."
"Because we wondered if there would a long line at security," said Jacob, who thanked the TSA workers who came to work Sunday. "We were here with plenty of time."
Editor's Note: This story has been updated to clarify that, according to the TSA, there was no indication the long lines on this particular weekend were caused by any officer callouts linked to the government shutdown.
ABC News' Amanda Maile, Meridith McGraw and Azure Gilman contributed to this report.