MADJIASRA NAKO and JOHN IRISH CHAD will deploy some 1,000 troops to the tri-border region of Niger, Burkina Faso and Mali to reinforce national armies that, backed by French and European allies, are battling Islamist insurgents, according to French and Chadian sources. The deployment will be announced during a summit on February 15-16 in the Chadian capital N'Djamena held to tackle the situation in the Sahel, a French presidency official and a senior Chadian security official said. It comes as France, which sent troops to the region in 2013 to help repel jihadists who had occupied northern Mali, considers adjusting…