The CIA is offering all of its employees incentives to resign — and some say its part of a move by US President Donald Trump to stack the government in his favour.

A lawsuit says the Trump administration's offer of a buyout to federal employees is unlawful, noting that Congress has not appropriated money for it.

CIA Director John Ratcliffe personally decided he also wanted the CIA to be involved, one of the sources said. The spokesperson said that the move is part of Ratcliffe's efforts to "ensure the CIA workforce is responsive to the Administration's national security priorities,