China and Russia have staged massive military drills in airspace and waters near the Korean Peninsula to counter a big U.S.-South Korea aerial exercise here this week.

In a statement from an air base in northern China on Monday, Chinese Air Force spokesman Shen Jinke said fighter jets and early warning aircraft conducted multiple drills in the West Sea and East China Sea recently, according to CCTV on Tuesday.

Shen said reconnaissance aircraft "took a flight path not previously flown to regions they had never previously operated in."

Chinese military affairs specialist Song Zhongping speculated that they were gathering intelligence on the ongoing joint South-U.S. exercise, which mobilized some 230 aircraft including stealth fighter jets and strategic bombers.

Some 1,000 marines from Russia's Pacific Fleet have been conducting a live-fire drill with tanks in in Siberia, including the border areas with North Korea, Newsweek reported Monday quoting a statement from the Russian Defense Ministry.

