U.S. troops deployed to the Calexico, California, area have been tasked with painting the border fences there to improve their “aesthetic appearance,” Sen. Dick Durbin, D-Ill., tweeted Wednesday.

The project will take about a month and cost about $150,000, a Customs and Border Protection official confirmed to CBS News, with the Homeland Security Department footing the bill.

“A disgraceful misuse of taxpayer $$,” Durbin wrote. “Our military has more important work to do than making Trump’s wall beautiful.”

About 5,000 active duty and National Guard troops have been sent to the border, mostly units specializing in intelligence and engineering, in response to President Trump’s efforts to stem border crossings by a recent influx of Central American migrants, a declared national emergency.

Their mission has included hanging concertina wire along existing barriers, but according to a copy of the email provided to CBS, an unspecified number of them have been assigned to fence beautification duties.

“While the primary purpose is to improve the aesthetic appearance of the wall, there may also be an operational benefit based on our experience with painted barrier in Nogales, Arizona," the DHS official wrote.

Those barriers were painted white, the email read, which contrasts sharply than the original brown, preventing camouflaging tactics by anyone crossing the border.

“These are soldiers, they are not painters," Texas Democrat Rep. Joaquin Castro told CBS.

Troops first set up at points along the nearly 2,000-mile border last year, and officials have not given a timeline for redeployment to their duty stations.