WASHINGTON — On Sunday, passengers at the globe’s busiest airport faced grueling five-hour waits as the TSA crisis intensified.

Transportation Secretary Sean Duffy cautioned that airport delays nationwide are poised to “worsen significantly” due to the partial shutdown impacting the Department of Homeland Security.

At Atlanta’s Hartsfield-Jackson International Airport, lines snaked around the facility on Monday.

Travelers were informed by TSA agents that wait times in certain sections of the airport—which saw 106 million passengers last year—could reach up to five hours, reported the Atlanta Journal-Constitution.

Already, nearly 400 TSA employees have resigned amid the DHS shutdown, and Duffy highlighted the risk of further resignations if a second paycheck isn’t received by Friday.

“As we approach Thursday, Friday, and Saturday of next week, expect more TSA agents to either resign or fail to report for duty,” Duffy told ABC News’ “This Week” on Sunday.

“I do think it’s going to get much worse, and as it gets worse, I think that puts pressure on the Congress to come to a resolution.”

DHS has been in a partial shutdown since Feb. 14, with Democrats filibustering a funding measure in the Senate until they get their demands for sweeping reforms to ICE and other immigration enforcement reforms.

Wait times at TSA security lines have exploded in the time since, with major travel hubs such as LaGuardia Airport and elsewhere blowing past three hours amid a shortage of workers.

In addition to employees outright quitting, call-out rates have rocketed, jumping from an average of 2% before the partial shutdown to over 10%, according to acting Deputy TSA Administrator Adam Stahl.

Stahl also warned that some small airports may be forced to close down if the funding lapse continues.

TSA workers last received a full paycheck on Feb. 14, then got a partial one on Feb. 28 and missed their next pay period on March 13, according to an agency spokesperson.

“A lot of the starting salaries at TSA, they’re right around $50,000,” Duffy explained. “It’s hard for these individuals already to make their ends meet. But without getting paychecks, it’s even that much more challenging.”

This is the third shutdown in the past six months that TSA employees have endured, including the 43-day one last fall and a short one at the start of the year that didn’t impact pay.

To mitigate airport chaos, President Trump announced plans to deploy Immigration and Customs Enforcement (ICE) agents to airports to ease the strain on TSA, starting Monday.

“The president’s looking around every corner to make sure the American people don’t suffer during the shutdown,” Duffy said.

“They [ICE] run those same type of security machines at the southern border, right?” he replied when pressed about the qualification of ICE to secure airports. “Packages come through or people come through. They run similar assets.”

Trump on Sunday publicly tied a funding deal for the DHS to his demands that the Senate pass the SAVE America Act, which would enact a proof-of-citizenship requirement to vote and other conservative wishlist items.

Meanwhile, DHS is gearing up for new leadership after the Senate advanced the nomination of Sen. Markwayne Mullins (R-Okla.) to helm the department on Sunday, teeing up a final confirmation vote this week.