"We must find a way to review our Sahel policy in the light of current developments, as well as our policy towards Gabon, which is also in the midst of a coup since yesterday," Borrell told reporters after the EU informal ministerial meeting on foreign affairs in Spain's Toledo.
However, the EU assesses the situations in Niger and Gabon differently, despite the fact that military takeovers took place in both countries, he added.
"I would like to point out the difference between the situations in Niger and Gabon. In Niger, [ousted President Mohamed] Bazoum was the only democratically elected president in the entire Sahel region, while as for the elections in Gabon, we have doubts about their democratic nature. We should not treat both situations equally," Borrell said.
The EU supports a political dialogue with Gabon and the restoration of a "real, and not a dummy democratic government," the foreign policy chief added.
The military took control of Niger on July 26 after Bazoum was ousted and detained by his own guard, led by General Abdourahmane Tchiani. Subsequently, the Economic Community of West African States (ECOWAS) suspended all cooperation with Niger and threatened invasion if the leadership do not reinstate Bazoum.
By early August, during a summit in the Nigerian capital of Abuja, ECOWAS leaders agreed to activate a standby force to potentially compel the Nigerien military to reinstate Bazoum. On August 18, ECOWAS Commissioner for Political Affairs Abdel-Fatau Musah said the block's general staff chiefs had agreed on the date for invading Niger but would not make it public.