washington u.s. defense secretary jim mattis say tuesday unite state would try one time work pakistan afghanistan president donald trump would turn options address islamabad allege support militant group relations two countries fray past decade officials long question role pakistan play afghanistan comment mattis likely cause concern islamabad within pakistan military need try one time make strategy work pakistanis best efforts fail president prepare take whatever step necessary mattis say house arm service committee hear mattis add would travel islamabad soon give detail reuters first report possible trump administration responses discuss include expand u.s. drone strike perhaps eventually downgrade pakistan status major non-nato ally ask lawmaker whether revoke pakistan major non-nato ally status amongst options consider deal islamabad mattis say sure separate senate hear tuesday top u.s. military officer say believe pakistan main spy agency inter-services intelligence isi directorate tie militant group clear isi connections terrorist group marine corps general joseph dunford chairman joint chiefs staff tell senate arm service committee pakistan embassy washington say islamabad achieve success counter-terrorism operations country however unless level success achieve afghanistan long last peace region remain reach embassy say statement unite state 2012 designate pakistan-based haqqani network terrorist organization year u.s. navy admiral mike mullen top u.s. military officer cause stir tell congress haqqani network veritable arm isi directorate u.s. officials tell reuters unite state send 3,500 additional troop afghanistan dunford say current cost unite state afghanistan 12.5 billion year new strategy would cost additional 1.1 billion mattis say try work pakistan 'one time