The National Science Foundation, an independent federal government agency that is one of the cornerstones of public research funding in the U.S., said Tuesday it has laid off approximately 12% of its workforce.

An NSF spokesperson told CBS News that 168 probationary employees were let go. Before Tuesday, the spokesperson said the agency had approximately 1,450 employees.

"We thank these employees for their service to the NSF and their contributions to advance the agency mission," the spokesperson said.

The layoffs allow the agency to comply with President Donald Trump's executive order issued Feb. 11 that requires a reduction in force of temporary federal employees, of which there a more than 200,000, according to multiple media outlets.

Some of the 168 people impacted worked within physics-centric scientific areas, including probationary staff as well as "expert" employees with specialized research backgrounds who were hired on a part-time basis, Nextgov/FCW reported.

This is not the first federal agency related to science and public health to announce probationary layoffs. Approximately 1,300 employees at the U.S. Centers for Disease Control and Prevention reportedly were laid off Friday, about 10% of its workforce. An estimated 1,200 employees at the National Institutes of Health, the nation's premier biomedical research agency, have been dismissed, according to The New York Times.

NSF employees were told earlier this month to expect a 25% to 50% reduction in their workforce, the Times reported, citing a person familiar with the matter who spoke on the condition of anonymity because the person was not authorized to discuss the plans publicly.

Federal workers are in a probationary period that typically extends for one to two years of employment and do not receive the same civil service protections as other federal employees, according to CBS News.

The Office of Personnel Management on Jan. 28 offered a deferred resignation program for federal employees, giving them full pay and benefits until Sept. 30 for those who agreed to leave. The White House said 75,000 signed up, and a federal judge cleared a legal roadblock last week for the program to move forward, according to CBS News.

But the number of workers who took the deferred offer was less than the administration's target, leading to the administration's focus to lay off nearly all probationary workers.

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