Burkina Faso has formally notified the Economic Community of West African States (ECOWAS) of its decision to leave the bloc, Reuters reported Tuesday. 

On Sunday, military officials of Mali, Burkina Faso and Niger announced in a joint statement that they are no longer members of the ECOWAS.

But the 15-member block later officially asserted the three nations remain its integral members, saying it is yet to receive any direct notification from the three member states about their intention to withdraw from the community.

ECOWAS was founded in 1975 with a mission to promote economic integration in all fields of economic activities, particularly industry, transport, telecommunications, energy, agriculture, natural resources, commerce, monetary and financial affairs, and social and cultural matters. 

To demand a return to constitutional order, ECOWAS, with headquarters in Abuja, the capital of Nigeria, has imposed drastic sanctions on Mali, Burkina Faso and Niger since the military took power in the three countries.

(With input from agencies)