It crosses the Afghan-Pakistan border about 80 km southwest of Jalalabad , and joins the Indus near Isa Khel after a course of more than 320 km ( 200 miles ) . It crosses the Afghan-Pakistan border about 80 km southwest of Jalalabad , and joins the Indus River near Isa Khel after a course of more than 320 km ( 200 miles ) .