In a show of unity, the U.S., Japan and South Korea are demanding that North Korea stop provoking Seoul and take concrete steps to reverse its nuclear weapons program.

At a news conference with her Japanese and South Korean counterparts, Secretary of State Hillary Rodham Clinton said the three agree that there should be no direct talks with North Korea until it changes course.

Clinton said China's proposal for a resumption of nuclear talks with North Korea is "appreciated" by the U.S., Japan and South Korea. But she said that should not happen until North Korea halts what she described as "provocative and belligerent" behavior, following the deadly shelling last month of a South Korean island.

THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP's earlier story is below.

WASHINGTON (AP) — The top U.S. military officer will visit South Korea this week to reassure Seoul in the wake of a series of provocative actions by North Korea.

The chairman of the Joint Chiefs of Staff, Adm. Mike Mullen, will meet Wednesday with his South Korean counterpart and other senior military and civilian defense officials, Mullen spokesman Capt. John Kirby said Monday.

"The principal message is to the South Koreans and that we continue to be stand by them," he said.

Mullen is the top military adviser to President Barack Obama and Defense Secretary Robert Gates.

The Seoul meeting is another sign of U.S. concern about rising tensions on the Korean peninsula. Obama called Chinese President Hu Jintao on Sunday night to discuss North Korea, the White House said, and urged China's president to send North Korea a message that "its provocations are unacceptable."

Secretary of State Hillary Rodham Clinton also was meeting at the State Department on Monday with her Japanese and South Korean counterparts to discuss the way ahead with North Korea.

"This meeting takes place at a time of grave concern in Northeast Asia amid the provocative attacks from North Korea," Clinton said at the beginning of the talks.

Gates, speaking to U.S. sailors aboard the USS Abraham Lincoln in the Arabian Sea, also weighed in on the tensions.

"We need to figure out the way ahead with North Korea," he said. "Nobody wants a war on the Korean peninsula. And I think we just have to work with the Chinese and with others to see if we can't bring some greater stability, some greater predictability to the regime in Pyongyang."

Kirby said the Obama administration late last week decided to dispatch Mullen to South Korea following tensions generated by the Nov. 23 shelling of Yeonpyeong Island by North Korean forces as well as heightened concerns that North Korea may be expanding its nuclear weapons program.

Kirby said Mullen intends to discuss ways to improve U.S.-South Korean defense cooperation.

"Given the ongoing tensions on the (Korean) peninsula, ... this presented a good opportunity to reaffirm and reassure the South Koreans of our commitment to the alliance," Kirby said.

The U.S. intervened in support of South Korea when North Korea invaded in June 1950 and is party to an armistice agreement that ended the fighting in July 1953.


Associated Press Broadcast correspondent Sagar Meghani contributed to this report.