On Wednesday, the EU said in a statement that it "considers the emergency measures taken by the military leaders who seized power ... relieving the president of the republic of his duties to be completely unlawful," a statement on behalf of the union said.

The 27-member bloc is Mauritania's biggest aid donor.

'Serious' risk of isolation

The EU sent a warning "(to) the military junta of the serious risk of the country's long-term isolation in the international arena."

"It urges the junta to restore the institutional framework that existed before August 6," the statement from the French government, which currently holds the EU's rotating presidency, said.

Military leaders overthrew the Mauritanian government on August 6, in apparent retaliation for the sacking of four top officers.