The president of Belarus has shown defiance in the face of US pressure
The US has said that Belarus' decision to order the expulsion of 10 US diplomats is unjustified.
Belarus summoned the highest US embassy official in Minsk to the foreign ministry on Wednesday, presenting him with a list of "personae non gratae".
The ex-Soviet republic's latest move follows the expulsion of the US ambassador in March.
US State Department Spokesperson Sean McCormack said the action was both unfair and "unwarranted".
"We are considering our response to this action," Mr McCormack said, according to Reuters.
A senior US diplomat, Jonathan Moore, said he had been given a list of 10 US diplomats who had been ordered to leave within 72 hours.
He said they would do everything possible to comply with the request and ensure the staff left the country within the set time limit.
The US embassy says it currently has 15 diplomats in Minsk.
The diplomatic expulsions were initially ordered after Washington imposed sanctions on the country's state-controlled oil-processing and chemicals company, Belneftekhim.
The firm accounts for about a third of the country's foreign currency earnings.
Belarus said its embassy staff in Washington had been cut to six, but that the US had not cut staff enough.
The US - along with the European Union - has also restricted the travel of authoritarian President Alexander Lukashenko and members of his inner circle.
In his annual address to the nation on Tuesday, Mr Lukashenko expressed defiance over pressure from the US and EU to free political prisoners in order to improve ties.
"If the Americans introduce new sanctions and think we will collapse, that's rubbish," he said, adding that no political prisoners would be released.