SINGAPORE >> China’s aggressive moves to claim jurisdiction over land and sky in the Asia-Pacific risk undermining peace and security in the region and beyond, U.S. Defense Secretary Chuck Hagel said Saturday. Beijing scoffed at the “groundless” charges.

Hagel told an international security conference that the United States “will not look the other way” when China and others try to restrict navigation or ignore international rules and standards.

China’s territorial claims in the South China Sea are destabilizing the region, he said, adding that Beijing’s failure to resolve such disputes threatens East Asia’s long-term progress.

A Chinese general took issue with Hagel’s comments, saying that “although I do think that those criticisms are groundless, I do appreciate your candor.”

Lt. Gen. Wang Guanzhong, deputy chief of the General Staff, told Hagel during a brief meeting after the defense secretary’s speech, “You were very candid this morning and, to be frank, more than our expectation.”

Reporters were taken from the meeting room before Hagel responded. But Pentagon press secretary Rear Adm. John Kirby said Hagel told Wang that all regional disputes should be solved through diplomacy, and Hagel encouraged China to foster dialogue with neighboring nations.

As he did in 2013, Hagel used his appearance at the Shangri-La conference to single out China for cyberspying against the U.S. While this has been a persistent complaint by the U.S., it was less than two weeks after the Obama administration charged five Chinese military officers with hacking into American companies to steal trade secrets.

The Chinese, in response, suspended participation in a U.S.-China Cyber Working Group, and released a report that said the U.S. is conducting unscrupulous cyberespionage and that China is a major target.

Noting the suspension, Hagel said the U.S. will continue to raise cyberissues with the Chinese “because dialogue is essential for reducing the risk of miscalculation and escalation in cyberspace.”

In comments aimed directly at China, Hagel said the U.S. opposes any country’s use of intimidation or threat of force to assert territorial claims.

“All nations of the region, including China, have a choice: to unite, and recommit to a stable regional order, or, to walk away from that commitment and risk the peace and security that has benefited millions of people throughout the Asia-Pacific, and billions of people around the world,” he said.

China and Japan have been at odds over uninhabited islands in the East China Sea that are controlled by Japan but claimed by both.

The U.S. has declined to take sides, but has made clear it has a treaty obligation to support Japan. The U.S. also has refused to recognize China’s declaration of an air defense zone over a large swath of the East China Sea, including the disputed islands.

In response, Maj. Gen. Yao Yunzhu of China’s People’s Liberation Army questioned whether the U.S. and its allies followed international law and consulted with others whey they set up air defense zones.

Yao, director of the Center for China-America Defense Relations at the PLA’s Academy of Military Science, also challenged how the U.S. can say it is not taking a position on the island sovereignty issue, while still saying it is committed to its treaty obligation to support Japan.

Hagel said the U.S. and allies consulted with its neighbors and, unlike China, did not unilaterally set up air defense zones.

While the two public exchanges with the Chinese officials were sharp, a senior U.S. defense official described Hagel’s private meeting with Wang as fairly amicable.

The official, who was not authorized to discuss the meeting publicly and spoke on condition of anonymity, said Wang began by criticizing the speech, but also talked about increasing military cooperation with the U.S. and the two nations’ trade relationship.

The official said Wang indicated China was looking forward to participating in a major military exercise in the Pacific with the U.S. and other nations later this year.

U.S. officials also have raised concerns about Beijing’s decision to place an oil rig in part of the South China Sea also claimed by Vietnam. The move has led to a series of clashes between the two nations in the waters around the rig, including the recent sinking of a Vietnamese fishing boat.

Chinese leaders have blamed the Obama administration’s new focus on Asia for emboldening some of the disputes.

But some Asian leaders have expressed worries that the U.S. is doing little more than paying lip service to the complaints, fueling doubts about America’s commitment to the region.

In an effort to address those concerns, Hagel also used his speech to reassure Asia-Pacific nations that despite persistent budget woes and increasing demands for military aid across Africa and Europe, the U.S. was strongly committed to Asia.

Allies have questioned how serious the U.S. is about its renewed focus on Asia, particularly as the recent unrest in Ukraine and terrorist threats in North Africa have garnered more attention. Also, President Barack Obama’s national security speech this past week made no mention of the Asia-Pacific.

“The rebalance is not a goal, not a promise or a vision — it is a reality,” Hagel said.

He laid out a list of moves the U.S. has made to increase troops, ships and military assets in the region, provide missile defense systems to Japan, sell sophisticated drones and other aircraft to Korea, and expand defense cooperation with Australia, New Zealand and India.