Building off its purchase of eight new F-16 jets as part of a more-than-$1 billion deal two years ago, the Bulgarian government continues to eye a follow-on agreement for additional aircraft as part of a discussion that is "still in the works," a U.S. Air Force official said today. The country is just one of a series of foreign partners that have expressed interest in F-16s recently, aircraft that Col. Anthony Walker, senior materiel leader in the international division, said...