The full extent of the order was not immediately clear, but the directive sent to government agencies on Monday threatened to paralyze a vast swath of federal programs.

US President Donald Trump has offered federal workers the option to resign and receive pay for eight months, in a major effort to shrink and reform the US government. In an email, his administration has asked almost all government employees to decide by 6 February whether they want to be part of a "deferred resignation" programme that will mean them leaving their jobs no later than the end of September.

Employees have until Feb. 6 to decide whether to take the buyouts offered by OPM or return to the office— in most cases, five days a week.