The required notification was given by the U.S. Defense Security Cooperation Agency, which said the U.S. State Department had signed off on the Foreign Military Sales request.
"The government of the United Kingdom has requested continued participation in the USAF/Boeing Globemaster III Sustainment Partnership, which consists of support for the United Kingdom's fleet of eight Boeing C-17A Globemaster III cargo aircraft, contractor technical and logistics personnel services, support equipment, spare and repair parts, and other related elements of logistics support," it said.
"The support will provide UK with rapid global strategic mobility to deploy to austere locations."
The proposed package deal for Britain would be worth an estimated $250 million.
The C-17 came into service in 1995 and has a paload of 170,900 pounds. It has a range of nearly 2,800 miles and is capable of carrying armored vehicles as well as troops.