The US has been increasing air and sea reconnaissance in waters near China, a situation that Beijing regards as dangerous and harmful to the building of trust between the two nations, a senior Chinese military officer warned on Tuesday.

US surveillance activities around China are soaring, while US vessels and planes are coming closer to Chinese ships and aircraft in China's exclusive economic zones in the East China Sea and the South China Sea, said Guan Youfei, director of the Foreign Affairs Office of the Ministry of National Defense.

"Any country would feel uneasy and threatened under such high-frequency reconnaissance," Guan said. "It goes against the good momentum of building a new type of relationship between the two militaries."

Meanwhile, China expressed serious concerns over the Taiwan Policy Act of 2013, approved by the US House of Representatives' Foreign Affairs Committee in August, which authorized US President Barack Obama to accept Taiwan's request for the purchase of F-16 fighters, Guan said.

"We hope Washington will have a clearer vision of the situation and stop repeating its mistakes on the Taiwan question," he said at a news briefing in Washington after the conclusion of Defense Minister Chang Wanquan's four-day visit to the US.

Chang, during his first trip to the Pentagon since assuming office in March, met separately on Monday with his US counterpart, Chuck Hagel, and US National Security Advisor Susan Rice.

Meng Xiangqing, deputy director of the Strategic Research Institute at the National Defense University of the People's Liberation Army, said the development of Sino-US military ties hinges on prioritizing cooperation and controlling major divergences.

Resolving differences

"Boosted by growing shared interests, the two militaries have already laid a sound basis for cooperation, but the Pentagon has to take concrete steps to remove the barriers," Meng said.

"US reconnaissance activities have always been a thorny maritime issue between the two countries. If Washington continues its stubborn conduct, the possibility of confrontation between the two countries' vessels and planes will grow, and this may lead to an accidental clash," Guan said.

China urged the US to think wisely and strategically on the issue, reducing and gradually ceasing all reconnaissance activities in China's waters.

Apart from the issue of reconnaissance, stumbling blocks for the two militaries include US arms sales to Taiwan, and the US Congress' discriminatory legislation on China, Guan said.

US arms sales to Taiwan reached a total of $27 billion over the last 10 years, an increase of $8 billion compared with that of the previous 10 years, according to Guan.

He said Beijing had proposed the establishment of working groups to further discuss these issues with the US and find solutions to major divergences. Washington responded positively, calling it an effective way to resolve bilateral differences.

Meng said the agreement to launch the working groups signals the two countries' shared aspirations and efforts to tackle ongoing problems, but all the differences cannot be resolved overnight.

"Sino-US ties have been suspended four times during the past 20 years, either because of arms sales to Taiwan or the reconnaissance activities, and Washington has not made substantial changes during all these years," Meng said.

"China calls for the US to take pragmatic measures to live up to its words," he added.

On the contentious issue of Internet security, Guan said Washington adopts double standards in light of the US PRISM project, revealed by former CIA contractor-turned-whistle-blower Edward Snowden.

During Monday's talks, both Chang and Hagel welcomed the recent establishment of the US-China cyber working group to address the issue.

"The Chinese military has never supported cyberhacking," Chang reiterated.

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