China on Wednesday expressed concern over the military exercises to be held late July by the Republic of Korea (ROK) and the United States in the Japan Sea.

Naval and air forces of the two allies will take part in a series of joint drills next week, the Joint Chiefs of Staff in Seoul said Tuesday.

The first joint exercise will involve the U.S. aircraft carrier USS George Washington and start July 25 in the Japan Sea. The two sides plan to stage other drills in both the Japan Sea and the Yellow Sea, too.

"We firmly oppose foreign warships and military aircraft entering the Yellow Sea and other coastal waters of China to engage in activities affecting China's security and interests," Qin Gang, a Foreign?Ministry spokesman?said when asked to comment on the drills.

Qin urged relevant parties to exercise calm and to refrain from acts that might escalate tension in the region.

"China's stance on the ROK-U.S. drills is clear...We will closely watch developments in the situation," Qin said.