Washington (CNN) The Trump administration is looking to the already stretched-thin US Marshals Service to take over protection duties for Cabinet-level officials not already protected by typical law enforcement personnel.

The plan, announced Thursday by the White House Office of Management and Budget, would mark a major departure from the Marshals' primary missions to protect federal judges and witnesses, transport prisoners and apprehend fugitives, and is already causing concern about how the agency would take on the task.

Marshals around the country received word from headquarters on Wednesday that the service was preparing for the move, a source familiar with the ongoing discussions said.

The proposal was tucked into a broader plan on government reorganization the White House released on Thursday.

"Consolidate protective details at certain civilian Executive Branch agencies under the US Marshals Service in order to more effectively and efficiently monitor and respond to potential threats," read the recommendation. "Threat assessments would be conducted with support from the US Secret Service."

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