BEIJING -- After three days of talks here, America's top military officer said Wednesday that he believed China wanted to limit the nuclear ambitions of North Korea but that it remained unclear how China would work toward that goal.
Contrary to suggestions by some in the United States that China was not interested in solving the North Korean problem, Gen. Martin E. Dempsey, the chairman of the Joint Chiefs of Staff, said the "Chinese leadership is as concerned as we are with North Korea's march toward nuclearization and ballistic missile technology."
"And they have given us an assurance that they are working on it, as we are." He added, "But I didn't gain any insights into particularly how they would do that."
General Dempsey met with the Chinese leadership Tuesday, including President Xi Jinping, and Gen. Fan Changlong, the vice chairman of the Central Military Commission that runs the Chinese Army, Navy and Air Force.
They were the most senior-level talks between the American and Chinese militaries in nearly two years. Because of the long gap in direct communication, and the growing distrust between the two sides over China's fast military modernization and China's assertive behavior in the East China and South China Seas, General Dempsey arrived with a major set of issues concerning China's military behavior.
As a symbol of how China's maritime power is growing, a senior Chinese military officer announced Tuesday in the middle of General Dempsey's visit that China would build a second aircraft carrier and that it would be more sophisticated than the first carrier launched last year. The officer, Song Xue, deputy chief of staff of the Chinese navy, said the "next aircraft carrier we need will be larger and carry more fighters."
At a news conference with foreign reporters based in China, General Dempsey said he warned the Chinese military leaders that the United States would abide by its alliance with Japan in the dispute between China and Japan over who owns the islands known as the Senkaku by Japan, and the Diaoyu by China.
Chinese vessels have been challenging Japanese ships off the islands, which are administered by Japan, since the dispute erupted last September, and Xi Jinping, who was vice president at the time, advised the United States to keep out of the argument.
On Tuesday, eight Chinese patrol ships approached the islands, the largest contingent to appear at one time since September. The Chinese state-run news agency, Xinhua, said the Chinese ships had forced Japanese fishing boats out of the waters around the islands.
Western defense analysts have said the Chinese continue to send surveillance vessels close by the islands in order to test whether the United States will live up to its alliance obligations with Japan.
General Dempsey said he left no doubt in his discussions with Chinese officials that "we do have certain treaty obligations with Japan that we would honor."
On the contentious issue of cyberattacks, General Dempsey said he asked the Chinese "to put a team of their best and brightest" together to work with the Americans on seeking rules of conduct on computer security.
In the past month, the Obama administration has criticized China for what it calls a mounting body of evidence that the Chinese military was involved in the widespread theft of data from American computer networks, particularly those of American corporations.
China's leadership appears to have heard the Obama administration's admonitions that it would not tolerate the Chinese practice of cyberattacks aimed at intellectual property and gaining commercial secrets from American businesses, American officials say.
The Chinese agreed during a recent visit of Secretary of State John Kerry to join a "cyber working group" with the Americans. "There has to be some kind of code of conduct established," General Dempsey said.
But the Chinese apparently did not give any answers to General Dempsey on whether they intended to stop these activities as specifically requested by the Obama administration.
At the start of General Dempsey's visit on Monday, a senior Chinese general, Fang Fenghui, said that breaches in cybersecurity could result in as much damage as a nuclear attack.
This article originally appeared in The New York Times.