Up to 5,000 troops are to be sent by the African Union (AU) to Burundi in a bid to stop the country’s descent towards civil war.
The 54-member bloc has given the government in the capital Bujumbura four days to agree to the deployment of military personnel and police.
In a statement, the AU’s Peace and Security Council warned it would “take all appropriate measures against any party or actor, whomsoever, who would impede the implementation of the present decision”.
Burundi’s government dismissed the AU’s statement, with spokesman Philippe Nzobonariba telling state radio: “They can’t invade a country if the latter is not informed and allow it.”
Mr Nzobonariba blamed neighbouring Rwanda for the recent chaos, where leaders are accused of supporting rebels who recruit Burundian refugees.