The US has agreed for the first time to sell new AH-64E Apache attack helicopters to Indonesia, US officials say.
The deal is worth $500m (£320m), including radar, training and maintenance.
Indonesia will purchase eight new Apache helicopters, made by Boeing.
The deal was announced during a visit by US Defence Secretary Chuck Hagel, who is on a tour of South East Asia, to Jakarta.
"Providing Indonesia these world-class helicopters is an example of our commitment to help build Indonesia's military capability," he said in a statement.
The deal will help Indonesia respond to "a range of contingencies including counter-piracy operations and maritime awareness", it said.
The US has recently stepped up its diplomatic efforts in East Asia in order to establish a strong presence there in the face of advances by China, correspondents say.
" Let there be among you a group that invites to the good, orders what is right and forbids what is evil, and they are those who are successful "[TMQ 3:104]