Niger last week missed a debt payment of 13.4 billion CFA francs ($22 million), the West African debt management agency said on Monday, bringing the total default to some $519 million since a July coup and its suspension from regional financial markets.

The West African monetary union debt management agency UMOA Titres said in a statement that Niger had failed to make a repayment of principal which was due on Feb. 16.

It noted that this occurred in the context of Niger being subject to sanctions imposed by the conference of heads of state and government of the West African Economic and Monetary Union (known by its French acronym, UEMOA). "This situation is carefully monitored by UMOA-Titres in collaboration with the institutions concerned," it said in a statement.

Niger has been suspended from the regional financial market, and the regional central bank by the Economic Community of West African States (ECOWAS) and UEMOA following a military coup in July that ousted President Mohamed Bazoum.

The country announced last month, along with neighbours Mali and Burkina Faso, that it was leaving ECOWAS with immediate effect. The regional bloc has a summit planned for Feb. 24 to discuss the situation.

($1 = 604.0000 CFA francs) (Reporting by Nellie Peyton, editing by Ed Osmond)