(CNN) -- Amid heightened tensions with North Korea, the United States and South Korea on Sunday began joint military exercises, according to a spokesman for U.S. Forces Korea.
The military exercise, dubbed Invincible Spirit, is scheduled to run through Wednesday and demonstrate the alliance's resolve. In addition to the 8,000 personnel involved, military officials say, it will include 20 ships and submarines and about 200 aircraft.
The U.S. Defense Department said the drills are in response to the sinking of the South Korean warship Cheonan and are intended to send a strong message to Pyongyang to stop "provocative and warlike acts".
North Korea criticized the exercises, which began at 6:30 a.m. (5:30 p.m. ET).
"The U.S. provocations amount to trespassing on the off-limits fixed by the DPRK and it, therefore, feels no need to remain bounded to the off-limits drawn by the U.S.," the state-run Korean Central News Agency quoted a North Korean foreign ministry spokesman as saying.
CNN
