The United States Undersecretary for Defence Douglas Feith says the US is considering a request by Islamabad to buy a number of F-16 fighter aircraft.
He was speaking in Pakistan where he has been holding security talks.
Pakistan has been trying for 15 years to acquire the planes, but correspondents say Washington's response has been muted so far.
Pakistani Defence Secretary Hamid Nawaz has said there's a lot of hope that the deal will finally be completed.
Mr Feith also demanded Pakistan do more to stop the flow of recruits into militant groups, arguing this was the only way to win the war on terror.
Last year Washington declared Pakistan a major non-NATO ally.