Niger’s military junta says it is severing military agreements with France, its former colonial ruler, firing some of the previous government’s key ambassadors and warning citizens of the West African nation to watch for foreign armies and spies. A regional delegation’s efforts at negotiation quickly deadlocked.

The junta’s announcement on state television late Thursday deepens the post-coup isolation for what had been the United States’ and allies’ last major security partner in the Sahel, the vast region south of the Sahara Desert that various Islamic extremist groups have turned into the global centre of terrorism.