Defense Secretary Chuck Hagel and Chinese Minister of Defense Chang Wanquan listen to the U.S. national anthem during a welcome ceremony at the Chinese Defense Ministry headquarters before their meeting Tuesday in Beijing. (Alex Wong/AP)

Near a banner offering him a “warm welcome,” Defense Secretary Chuck Hagel urged officers at China’s premier military university to work toward a new era of cooperation between the world’s top military rivals.

But during his first trip to China as Pentagon chief, icy body language and barbs telegraphed a relationship utterly devoid of warmth and very much saddled by suspicion.

Chinese Defense Minister Chang Wanquan offered a defiant defense of Beijing’s territorial claims over two sets of islands contested by Japan and the Philippines, disputes that are particularly vexing for Washington because it has defense treaties with both nations.

“On this issue, we will make no compromise, no concession — not even a tiny violation is allowed,” the Chinese minister warned sternly. “We are prepared at any time to cope with any type of threats and challenges.”

Chinese officials have long viewed the Obama administration's policy to expand military and diplomatic engagements in Asia as an effort to contain Beijing's military rise and bolster its rivals in the region. U.S. officials have made a concerted effort to dispel that narrative, saying they welcome a rising China, as long as it acts in a way they deem constructive. That effort has a long way to go.

After Hagel wrapped up his afternoon speech with tales of a friendly exchange over the radio between sailors aboard U.S. and Chinese ships that crossed paths in the East China Sea, the tone once again turned confrontational.

A researcher at the school demanded to know whether the United States was taking the side of Japan and the Philippines in the territorial disputes to create havoc for China and stymie its military rise.

“You are using the excuses of the islands to make trouble for China to hamper its [military] development,” said the officer. “That is what we worry about.”

While the bulk of Hagel’s remarks Thursday were conciliatory and forward-looking, he wagged his finger at one point, protesting China’s surprise establishment last year of an air defense zone in an area that includes the islands that are the subject of Beijing’s dispute with Tokyo.

“Every nation has the right to establish air defense zones, but not a right to do it unilaterally, without consultation,” Hagel told reporters, speaking alongside his Chinese counterpart.

As China has invested mightily in defense in recent years, the United States has become keenly interested in and alarmed by its capabilities, particularly in cyberspace. U.S. officials have begun urging China to be more transparent about its expanding military complex.

During his speech, Hagel said that the Pentagon recently offered Chinese officials a briefing about Washington’s evolving cyberwarfare doctrine.

“We are urging China to do the same,” Hagel said, noting that Beijing has refrained from divulging much about a program widely regarded as among the most aggressive and advanced in the world.

The Chinese defense minister rejected the notion that China has an offensive Internet program, which was first reported by the New York Times.

“The U.S. wants transparency in things it wants to know,” said Chu Shulong, a professor at Tsinghua University who focuses on U.S.-Chinese relations. “However, when it comes to things that the U.S. doesn’t want to disclose, it dismisses transparency.”

Pentagon officials say that China has taken modest, albeit significant, steps in recent years to broaden lines of dialogue and offer U.S. officials some insight into its new platforms and technology.

As China’s military continues to grow, Hagel said in the speech, “American and Chinese forces will be drawn into closer proximity – which increases the risk of an incident, accident or miscalculation.”

Seeking to avoid that, the two countries have agreed to establish a mechanism to warn each other about major military operations. China has also hosted several senior U.S. military officials, including the chairman of the Joint Chiefs of Staff and the heads of the Air Force, the Army and the Navy.

Upon Hagel’s arrival in China on Monday night, he was given a tour of the country’s first aircraft carrier, the Liaoning – an overture Pentagon officials saw as a significant confidence-building step. Chinese officials balked at a request by U.S. officials to allow Hagel’s traveling press corps to see the ship as well. Journalists were instead taken to tour a brewery.

Gu Jinglu in Beijing contributed to this report.