US subs reach Asian ports: report

Meanwhile, the US strengthened its relations with other allied countries in the Pacific region by conducting another war game.

The Rim of the Pacific Exercise (RIMPAC 2010), which is hosted and managed by the US Navy, launched June 23 as ships, aircraft and military personnel from 14 nations poured into Pearl Harbor, Hawaii, to participate, suite101.com reported.

The exercises will be conducted until August 1.

Meanwhile, Russia's Vostok-2010 military exercises in Siberia and the country's far east kicked off June 29 and will continue until July 8.

Analysts suggest that the concentration of military drills at the current time is not just a coincidence, but represents the uneasiness of some regional powers amid the rise of China.

Agencies contributed to this story