washington chairman senate foreign relations committee tuesday sharply question u.s. plan sell f-16 fighter jet pakistan question pakistani action describe threaten u.s. troop try stabilize afghanistan continue support taliban haqqani network give safe al qaeda republican senator bob corker say secretary state john kerry testify committee state department annual budget request u.s. government say feb. 12 approve sale pakistan eight f-16 fighter jet build lockheed martin corp radar equipment deal value 699 million lawmakers 30 days block sale corker make clear doubt kerry respond issue complicate say pakistan also ally understand reservations military deeply engage fight terrorism say u.s. senate committee chairman question pakistan f-16 deal