President Donald Trump said he’s considering sending the National Guard to U.S. airports, two days after the administration deployed Immigration and Customs Enforcement agents to several major U.S. airports following hourslong waits for travelers because of the partial government shutdown.

In a Truth Social post Wednesday, Trump blamed Democrats for the shutdown, which began Feb. 14.

“Thank you to our great ICE Patriots for helping. It makes a big difference,” he wrote in his post. “I may call up the National Guard for more help.”

More than 11% of TSA officers called out on Wednesday and over 450 have quit since the shutdown started, the Department of Homeland Security said.

Elevated absences of Transportation Security Administration officers, who are required to work though they’re not getting paid during the shutdown, have contributed to long lines at major U.S. airports, including in Atlanta, Houston and New York.

The DHS, which oversees both ICE and and the TSA, said the ICE agents will “support airports facing the greatest strain” but the department didn’t respond to requests for comment on what the ICE agents’ duties are. ICE agents are getting paid in the shutdown.

Airlines have been warning customers about potentially long security lines, while executives grow increasingly frustrated with lawmakers about the impasse. On Tuesday, Delta Air Lines said it suspended its airport escorts and other special services for members of Congress and their staff because of the ongoing partial shutdown of the DHS.

The shutdown comes as Democrats in Congress have demanded changes to how federal immigration enforcement operates in exchange for releasing DHS funding after two U.S. citizens were shot and killed by ICE officers in Minneapolis.