The British Navy will dispatch an aircraft carrier strike group to waters near Japan as soon as early next year, Japanese government sources said Saturday, in a rare development that comes amid the growing maritime assertiveness of China in the region.

The group, including the aircraft carrier Queen Elizabeth, is expected to conduct joint exercises with the U.S. military and Self-Defense Forces during its stay in areas including off the Nansei Island chain in southwestern Japan, the sources said.

It is unusual that countries other than those in the region as well as the United States conduct aircraft carrier operations in the western Pacific.

The move comes amid concerns over China's increasing assertiveness in the East and South China seas as well as about its handling of pro-democracy protesters in Hong Kong. It could trigger an outcry from Beijing.

During the dispatch, the British Navy also plans to conduct maintenance on carrier-based F-35B stealth fighter jets at Mitsubishi Heavy Industries Ltd.'s aerospace systems works in Aichi Prefecture, the sources said.

Britain announced last year it will dispatch the carrier group to the Pacific and has since been in talks with Japan and other relevant countries, they said.

The carrier, commissioned in 2017, is "the largest and most powerful vessel ever constructed" for the British Navy, weighing 65,000 tons and measuring 280 meters in length, according to the navy.