美核动力航母抵韩参加军演

The USS George Washington is the largest and most prominent of the 200 naval vessels participating in a four-day exercise off Korea's east coast. After departing its home port of Yokosuka, near Tokyo, in Japan, the nuclear-powered super-carrier paid a port call to Busan in South Korea. On Sunday, as the exercise began, the 333-meter long vessel headed into the Sea of Japan.

When the South Korean defense ministry originally announced this exercise, its official said the American aircraft carrier would go into the Yellow Sea -- between the Korean peninsula and China.

That prompted a strong protest from China. U.S. military officials deny they bowed to pressure from Beijing and moved the maneuvers from the Yellow Sea, saying the Sea of Japan actually is the most appropriate venue for this drill. But they say future exercises will be held off the west coast -- in the Yellow Sea.

That is where the South Korean warship, the Cheonan, exploded and sank in late March, killing 46 sailors. An international investigation concluded a North Korean torpedo hit the Cheonan. North Korea denies responsibility.

These war games are a direct response to the sinking of the South Korean vessel.

North Korea, as it has in the past, has reacted to the joint exercise with strong threats -- saying they may lead to a "sacred war" in which Pyongyang would be compelled to use its nuclear weapons.