The U.S. Department of Agriculture announced Tuesday that it will reopen all Farm Service Agency offices nationwide, temporarily calling nearly 10,000 furloughed federal employees back to work even as the longest-ever government shutdown dragged on.

The employees, whose local and state offices had been largely shuttered when a quarter of the federal government shut down in December, will be working without receiving regular paychecks.

The USDA said in a statement that President Donald Trump "has already signed legislation that guarantees employees will receive all backpay missed during the lapse in funding."

A department spokesperson confirmed to CNBC that the 9,700 recalled employees will not be paid until the government is reopened. "Like all federal employees affected by the lapse in funding, they will receive back pay under the legislation President Trump signed," the spokesperson said.

Agriculture Secretary Sonny Perdue thanked FSA staff in a tweet.

@SecretarySonny: Beginning Thursday, we are reopening ALL @usdafsa offices nationwide for a longer list of additional transactions during the partial government shutdown. Many thanks to FSA staff, dedicated to providing services to America's farmers.

As the shutdown of nine federal agencies enters its second month, the FSA's temporary reopening marks another government bureau's attempt to continue providing as many public services as they can in the face of a funding drought with no respite in view.

Last week, more than 46,000 furloughed IRS employees were called back to work just before tax season officially kicks off on Jan. 28. Airport security screeners working for the Transportation Security Administration have been working without regular pay throughout the shutdown, and the unpaid work has led to clogged check-in lines as record numbers of employees call out sick.

When it is fully open, the FSA provides a range of services to farmers and ranchers, such as providing support loans and certain emergency assistance programs.

Last Thursday, some FSA offices reopened to provide limited loan and tax document services. About 2,500 employees were called back at that time, the USDA said.

Beginning this Thursday, all of the agency's offices will open back up, and will offer a longer list of available services.

"At President Trump's direction, we have been working to alleviate the effects of the lapse in federal funding as best we can, and we are happy to announce the reopening of FSA offices for certain services," Perdue said in the statement.

"We want to offer as much assistance as possible until the partial government shutdown is resolved."