Washington (CNN) -- Pressure from China would be key to getting North Korea to change its behavior, the top U.S. military official said Wednesday.
"I believe that it's really important that Beijing lead here," Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, said in an interview to air Sunday on CNN's "Fareed Zakaria GPS."
He added, "I've believed for some time that probably the country that can influence North Korea the most is clearly China."
China, Mullen said, has much at stake in stopping North Korea's leader Kim Jong Il from taking more provocative actions.
"It destabilizes the region, and China has as much to lose as anybody in that region with the continuation of this kind of behavior and what the potential might be," he said.
The United States is hoping China, which North Korea relies on for economic support and trade, will exercise that influence.
President Obama will call President Hu Jintao of China in the next few days to discuss North Korea, administration officials said.
"China is pivotal to moving North Korea in a fundamentally different direction," State Department spokesman P.J. Crowley said Tuesday. "We would hope and expect that China would use that influence, first, to reduce tensions that have arisen from North Korean provocations and then, secondly, [to] continue to encourage North Korea to take affirmative steps to denuclearize."
The United States had "multiple conversations" with Chinese officials both in Beijing and in Washington in the initial day after the exchange of fire between North and South Korea on Tuesday, Crowley said.
For its part, China suggested Wednesday that it is ready to work with other countries to maintain stability in the region.
"We are ready to make joint efforts," a Chinese ministry spokesman said in a written statement.
While not condemning North Korea's actions, China maintained its position of promoting talks with Pyongyang.
"China strongly urges that both sides retain calm and restrain, and engage in talks as quickly as possible in order to prevent similar incidents from happening again," Chinese Foreign Ministry spokesman Hong Lei said in a statement. "Relevant parties should contribute more to efforts that will ease tensions and benefit the peace and stability of the peninsula."
North Korea does not appear to be preparing for further military attacks, which could calm the tensions with South Korea, Crowley said. While U.S. officials at the State Department and the Pentagon said the attack was a violation of the armistice that ended the fighting between the North and South in a stalemate in 1953, Crowley and the Pentagon's spokesman said it did not appear that North Korea intends a renewal of war.
"In our view, this was a one-off, premeditated act. Without getting into intelligence matters, we don't see that North Korea is preparing for an extended military confrontation," Crowley said.
"Certainly, attacking civilians takes this to a different level than what we've seen in the past," said Col. Dave Lapan of the Pentagon. "We continue to monitor the situation closely and look for any signals that might presage another aggression like that. So we are prepared."
Although the diplomatic talk is of restraint, Mullen was anything but diplomatic in describing North Korea's leader, who Mullen said is acting in an effort to set up a succession plan for his son, whom he recently elevated to the rank of four-star general in the Korean military.
Kim Jong Il "is belligerent, dangerous, consistently destabilizing and is only predictable in his unpredictability. And certainly he galvanizes everybody around, obviously, the potential that they could go to war with South Korea," Mullen said. "He's on a path to develop nuclear weapons, which is the most dangerous weapon in the world. And so this latest incident, I think, is certainly his continuation of that overall belligerence and unstable action plan that he's had in play for some time."
In the wake of the attack, the United States announced it will proceed with a planned naval exercise with South Korea. The exercise, to be held off the Korean Peninsula, will be a show of force meant to discourage any future attacks, Lapan said Wednesday.
"This exercise is directed at being a deterrent for the North Koreans," he said.
The USS George Washington carrier strike group will operate alongside Republic of Korea ships starting Sunday.
"It is an agreement between the U.S. and the Republic of Korea for those dates," Lapan said. "Those dates have been planned before the attack."
An official U.S. news release called the exercise "defensive in nature."
Lapan said the exercise in international waters will be similar to others in the past, including one with the George Washington last year.
CNN's Ed Henry contributed to this report.