President Donald Trump's administration will keep 611 essential workers on board at USAID, according to a notice sent to workers at the U.S. foreign aid agency late Thursday night and shared with Reuters by an administration official on Friday.

The administration had earlier planned to keep fewer than 300 staff at the U.S. Agency for International Development out of the agency's worldwide total of more than 10,000, Reuters previously reported, citing four sources familiar with the plan.

Washington's primary humanitarian aid agency has been a top target of a government reduction program spearheaded by billionaire and Trump ally Elon Musk since the Republican president took office on Jan. 20.

USAID's staff cuts will take effect at midnight on Friday, the notice said. However, a lawsuit filed on Thursday seeks to reverse the administration's aggressive dismantling of the agency, which distributes humanitarian aid around the world.

The lawsuit seeks a temporary and eventually permanent order from the court restoring USAID's funding, reopening its offices and blocking further orders to dissolve it.

The administration's dismantling of USAID comes amid a larger proposed buyout as Trump and Musk pressure federal workers to leave their jobs in an unprecedented drive to overhaul the federal government. That deadline has been extended until at least Monday pending separate court action.