U.S., S. Korea Launch War Games In Tense Yellow Sea A U.S. supercarrier and South Korean destroyer took up position in the tense Yellow Sea on Sunday for joint military exercises just days after a deadly North Korean artillery attack. As tensions escalated across the region, China belatedly jumped into the fray.

War Games Play Out In Tense Yellow Sea

North Korea is threatening a "merciless military counterattack" if its sovereignty is violated during joint U.S.-South Korean naval exercises this week.

The warning was published Sunday by Pyongyang's official Korean Central News Agency. In the commentary, the North criticized the large-scale drills, calling them "war maneuvers." Pentagon officials say the military training -- set to last until Dec. 1 -- is defensive in nature, but U.S. and South Korean officials say the broader message to North Korea is clear: America stands by its longtime ally.

The four-day exercises are being held in the Yellow Sea off the west coast of the Korean peninsula and not far from Yeonpyeong island, where last week's deadly exchange of fire between the two Koreas took place. Two South Korean marines and two civilians were killed, and 18 others wounded.

On the island Sunday, more artillery fire was heard from the North, but there were no reports of shells landing on the tiny South Korean territory. Still, the scare prompted the South's military to send remaining residents and journalists to bomb shelters. And later, the military ordered all reporters off the island, fearing "unpredictable provocative action" by North Korea.

China Urges Negotiations

To avoid a dangerous escalation of tension on the Korean peninsula, China on Sunday proposed talks next month on how to resume six-nation negotiations aimed at ending North Korea's nuclear weapons program. South Korea responded by saying only that it will cautiously review China's offer.

President Lee Myung-bak, speaking to a visiting senior Chinese diplomat, pushed for China to take a more responsible and fair position in its policies toward the two Koreas.

Appearing Sunday CNN's State of the Union, U.S. Sen. John McCain, the top Republican on the Senate Armed Services Committee, said China should rein in its neighbor.

"The key to this, obviously, is China," McCain said. "And, unfortunately, China is not behaving as a responsible world power. It cannot be in China's long-term interest to see a renewed conflict on the Korean peninsula."

South-North Relations Deteriorate

In a speech to the country Tuesday in South Korea, President Lee said he feels "deep responsibility" for failing to protect South Koreans from the deadly North Korean artillery attack. He said that the North will face consequences for future aggression, but didn't elaborate during the seven-minute speech.

The troubled relations between the two Koreas, which fought a three-year war in the 1950s, have steadily deteriorated since Lee's conservative government took power in 2008 with a tough new policy toward nuclear-armed North Korea.

Eight months ago, a South Korean warship went down in the western waters, killing 46 sailors in the worst attack on the South Korean military since the Korean War. Then, last Tuesday, North Korean troops showered artillery on Yeonpyeong, a South Korean-held island that houses military bases as well as a civilian population of 1,300 -- an attack that marked a new level of hostility.

North Korea has walked a path of defiance since launching a rocket in April 2009 in violation of U.N. Security Council resolutions and abandoning the disarmament process in protest against the condemnation that followed.

However, in recent months Pyongyang has shown an eagerness to get back to the talks, and has appeared increasingly frustrated by U.S. and South Korean reluctance to restart the negotiations.

Seoul has said it wants an acknowledgment of regret for the sinking of the Cheonan warship in March as well as a concrete show of commitment to denuclearization.

North Korea, which cites the U.S. military presence in South Korea as a main reason behind its drive to build atomic weapons, routinely calls the joint exercises between the allies a rehearsal for war.

Washington, which keeps 28,500 troops in South Korea to protect the ally, says the routine drills were planned before last Tuesday's attack.

The exercises will take place over four days, but no live-fire drills are planned, said Cmdr. Jeff Davis, spokesman for the 7th Fleet in Japan.

Calls for tougher action made way Sunday for pleas for peace among about 150 South Koreans who turned out for a vigil Sunday evening in a Seoul plaza, huddling with candles in paper cups and chanting, "Give us peace!"

"It was very shocking," said Kang Hong-koo, 22, a student. "I'm here to appease the souls of the people who were killed in the North Korean attack. I hope the current tense situation is alleviated quickly."

Doualy Xaykaothao contributed to this report, which contains material from the Associated Press.