The Obama administration will announce curbs on a significant part of nonessential military aid to Egypt within a few days, U.S. officials said Tuesday, marking a shift in American relations with one of its key Arab allies.

Officials would not provide figures about how much of an annual total of $1.2 billion in aid would be withheld, but said the primary focus will be a hold on shipment of a dozen AH-64D Apache helicopters from an order originally placed four years ago.

Provision of crucial spare parts for the extensive U.S. military equipment Egypt already has and training for the Egyptian armed forces will continue, officials said. They said aid that supports counterterrorism initiatives and ongoing Egyptian relations with Israel, including security efforts in the Sinai Peninsula and monitoring Egypt's border with the Gaza Strip, would also continue.