U.S. Senator Maria Cantwell joined a Mississippi Republican in asking the TSA not to remove screeners from airports for deployment to the US-Mexico Border.

Cantwell joined Sen. Roger Wicker in sending a letter to TSA leaders expressing concern over the plan.

This comes at the start of a busy weekend of travel for Memorial Day. Sea-Tac International Airport expects upwards of 500,000 passengers leading into the holiday weekend.

RELATED: Sea-Tac Airport braces for peak Memorial Day weekend traffic

"...the redeployment of hundreds of TSOs at the start of the summer travel season could increase wait times for travelers at airports across the country through summer and beyond,” Cantwell and Wicker wrote.

The Port of Seattle previously expressed concern over losing any TSA staff. Managing Director Lance Lyttle testified before lawmakers that Sea-Tac already struggles to retain TSA agents, and losing any could lead to “lines out to our parking garage as often as 4 to 5 days a week.”

RELATED: TSA shortage to blame for lengthy Sea-Tac Airport security lines, port says

He said large gatherings of people in the airport’s public space create customer service issues, as travelers experience long waits, but also security concerns, as these groups could become ‘soft targets.’

“The recent news of potential TSA staffing at the southern border has all airports very concerned,” Lyttle said.

Cantwell’s letter also addressed deployment of Federal Air Marshals (FAMs) to the border.

“While we acknowledge the request for additional resources from the Department of Homeland Security, we have concerns about the potential impact on executing TSA’s mission to ‘protect the nation’s transportation systems to ensure freedom of movement for people and commerce,’” Cantwell and Wicker wrote. “Deployment of FAMs would significantly diminish operational capacity, and diversion of funds may slow deployment of new computed tomography (CT) screening machines.”

TSA officials previously told KING 5 it is soliciting volunteers, and the group would be less than 1 percent of the workforce.