ISLAMABAD: Pakistan is in the final phases of striking a $1.5-billion deal to supply weapons and jets to Sudan, a former top air force official and three sources said, promising a major boost for Sudan’s army, battling the paramilitary Rapid Support Forces. Their conflict has stoked the world’s worst humanitarian crisis for more than 2-1/2 years, drawing in myriad foreign interests, and threatening to fragment the strategic Red Sea country, a major gold producer.