The signing of the long-expected China-US army dialogue mechanism and the country's upcoming agreement on the air-to-air annex to the code of conduct on military encounters represent a leap forward in the relationship between the countries, analysts have said.

　　However, they said the United States has to handle the South China Sea issue properly to maintain the positive momentum, and a Chinese military leader has warned Washington to be cautious in its words and deeds on key issues involving China's territorial integrity.

　　Central Military Commission Vice-Chairman Fan Changlong, who has just completed a visit to the US, urged Washington to reduce its military activities both in the air and in the waters of the South China Sea when meeting US government and military leaders.

　　Fan and US army Chief of Staff Raymond Odierno witnessed the signing of the dialogue mechanism at the National Defense University in Washington on Friday.

　　This is the first cooperation document to be signed by the two armies in recent years.

　　Guan Youfei, director of the Foreign Affairs Office of the Ministry of National Defense, said afterward that the two armies could hold joint exercises on land next year.

　　Guan said the two sides discussed mutual trust mechanisms for reporting major military operations and the code of conduct on military encounters in the air and at sea, both signed last year.

　　They vowed to reach agreement on the air-to-air annex to the code of conduct before President Xi Jinping visits the US in September.

　　Major General Yao Yunzhu, a senior researcher at the People's Liberation Army's Academy of Military Science, said, "The annex on air-to-air encounters aims to prevent crises, while the dialogue mechanism between the armies mainly helps with cooperation."

　　Guan said the two sides may hold joint exercises based on the code of conduct to make sure its terms are implemented correctly.

　　He added that, despite some objections, the US has invited China to attend the Rim of the Pacific exercise to be held next year.

　　Zhao Xiaozhuo, an expert on US military affairs at the academy, said Beijing has more ways to respond than before when the US tries to hamper China's legal interests.

　　"That is why Fan's US visit and the scheduled signing of the dialogue mechanism were not stalled by Washington's harsh stance on the South China Sea," he said.