Burkinabe soldiers aboard a military vehicle. AFP
Under the new law, Burkina can send a military contingent to Niger for a three-month renewable period.
It provides a legal framework for the deployment, whose mission would be to bring "military assistance to the Republic of Niger in the event of aggression or destabilisation by an external army, but also to fight against terrorism", Defence Minister Kassoum Coulibaly said.
Niger's democratically elected president, Mohamed Bazoum, was toppled by rebel officers on July 26.
They were swiftly supported by juntas in neighbouring Mali and Burkina Faso, whose presidents were likewise forced out following failures to stem a jihadist insurgency.
But the West African bloc ECOWAS has warned that it could intervene militarily in Niger if diplomatic efforts to return Bazoum to power fail -- a move that prompted Mali and Burkina to say any operation would be tantamount to a "declaration of war" on themselves.
The military leaders of the three countries on Saturday signed a mutual defence pact and Niger's new strongman, General Abdourahamane Tiani, has signed a decree authorising Mali and Burkina forces to intervene "in the event of external armed aggression or destabilisation."
The new Burkina Faso law allows it to set up "support points" in Niger to fight "terrorist groups which take refuge there often after committing attacks on our territory", said Coulibaly.
A region where the borders of Burkina, Niger and Mali meet has been ravaged by jihadism in recent years.
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