Australian troops drop packages to the island of MogMog in Micronesia as part of Operation Christmas Drop. Australian, Japanese and U.S. planes are taking part in the annual relief mission.

HONOLULU — Australian, Japanese and U.S. Air Force planes are dropping food and toys on remote atolls in the Pacific as part of the U.S. military's longest-running humanitarian relief mission.

The packages will support 20,000 people across 56 islands in Micronesia, the Mariana Islands and Palau.

The U.S. Air Force began the annual Operation Christmas Drop in 1952 when a Guam-based air crew noticed residents on an island waving as they flew overhead. The crew gathered items they had on the plane, attached a parachute and dropped them to the islanders.

It's a feel-good mission that also helps the U.S. achieve political aims, namely deepening three-way cooperation with close allies Australia and Japan, who are first-time participants. Analysts say the U.S. has been boosting the trilateral relationship in recent years as it keeps an eye on China's growing military.

The boxes include books, canned food and items like fishing nets that will help islanders maintain their largely subsistence lifestyle. This year, each package will also include a soccer ball.

The planes fly low, look for a safe spot to drop the bundles then release them from the back of the C-130s.