TOKYO — Defense Secretary Leon E. Panetta on Monday warned that territorial disputes between China and its neighbors could easily spiral into war, as the start of the fishing season in the East China Sea increased the likelihood of confrontations between Beijing and Tokyo over a string of islands there.
Mr. Panetta told reporters traveling with him in Asia that he will encourage Japanese and Chinese leaders to find a peaceful resolution to their competing claims to the islands, which are called Diaoyu in Chinese and Senkaku in Japanese.
Tensions between China and Japan spiked last week, when Beijing briefly sent six patrol ships off the islands’ coast after Tokyo had purchased the islands from a private Japanese business owner. Chinese citizens have protested against Japan in cities across China, in some incidents overturning Japanese-made cars and targeting Japanese businesses.
On Monday, the Kyodo news service cited a report on the state-run China National Radio that 1,000 Chinese fishing boats are expected to arrive in waters off the islands.
“We’re concerned by the demonstrations, and we’re concerned by the conflict that’s taking place over the Senkaku Islands,” Mr. Panetta said Monday.
In Asia to advance the Pentagon’s “pivot” to the Pacific region, Mr. Panetta met with Japanese Defense Minister Satoshi Morimoto and Foreign Minister Koichiro Gemba in Tokyo before traveling to nearby Yokota Air Base. There, he met with and addressed about 350 U.S. troops.
The defense secretary arrived Tuesday in Beijing, where he will meet with his counterpart, Gen. Liang Guanglie, and Vice President Xi Jinping, who is expected to be named president in the coming weeks.
“The United States does not take a position with regards to territorial disputes. But the one thing that I am urging is that countries develop a process to resolve these disputes peacefully. That’s what they have to do,” the defense secretary said before departing to China.
At the same time, the U.S. would stand by its treaty to defend Japan against attack, he added.
“Obviously, we stand by our treaty obligations. They’re long-standing, and that has not changed,” Mr. Panetta said. “Having said that, we expect that these issues will be resolved peacefully and, although we understand the differences here with regards to jurisdiction, it is extremely important that diplomatic means on both sides be used to try to constructively resolve these issues.”
Mr. Panetta warned there would be more territorial disputes like this, and urged both sides to abide by codes of conduct established by regional bodies, such as the Association of South East Asian Nation’s code of conduct for navigation rights.
“The reason this is happening is because a lot of these countries look to these islands, look to the resources that are out there, look to offshore drilling, look to energy resources. And so it’s going to become more competitive between countries as they face this issue,” he said.
The start of the fishing season Sunday in the East China Sea, where the Senkaku island chain lies between Japan and Taiwan, raises the chance of a confrontation leading to a flare-up, according to local media reports.
In previous years, Chinese authorities prohibited Chinese fishing ships from approaching waters near the islands to avoid the possibility of a confrontation between fishermen and Japanese coast guard vessels deployed there.
But this year, officials in Beijing have promised to protect fishermen by deploying paramilitary patrol vessels, “including in waters around the Diaoyou” as the Chinese call the island, according to Japan’s respected Asahi Shimbun newspaper.
Also Sunday, the People’s Liberation Army’s East China Sea Fleet staged its first live-fire military exercise in the area, according to state-run China Central Television.
The Pentagon announced Monday that the U.S. and Japan have agreed to begin coordinating the deployment of a surveillance radar designed specifically for ballistic missile defense.
It will be Japan’s second deployment of the Army Navy/Transportable Radar Surveillance and Control, or AN/TPY-2, which can track all classes of ballistic missiles and identify small objects at long distances, according to a Missile Defense Agency fact sheet. An AN/TPY radar already is deployed at Shariki, Japan.
A defense official said the radar deployment is not an act against China: “The radar would be focused on addressing the growing North Korean missile threat to the U.S. homeland, as well as U.S. citizens, our deployed forces, allies and partners in the region.”
There was no immediate response from Chinese officials about the radar.
“We have made great progress on this issue, important progress, and I believe we can expect a positive announcement soon,” Mr. Panetta said at a joint news conference with Mr. Morimoto, his Japanese counterpart.
The deployment of the tilt-rotor Ospreys is a sensitive issue for Okinawans. Before Mr. Panetta arrived in Tokyo, tens of thousands of Japanese had protested against the aircraft, which residents say is prone to crashes and risks the safety of people in densely populated Okinawa.
“We will do everything possible to respond to the concerns with regard to the Osprey,” Mr. Panetta said. “We will take whatever steps necessary to try to assure that the people involved are, and that the operations are safe, that we do whatever we can to provide noise abatement, that we will do whatever we can to assure the operations are in keeping with the neighbors that we have and that we respect at the base at Okinawa.”
• Shaun Waterman in Washington contributed to this report.