Sea confrontations surfaced as a thorny issue at the Sino-US Defense Consultative Talks that began Tuesday in Beijing.
Military sources told China Daily that 45 minutes of the three-and-a-half-hour session yesterday afternoon was dedicated to discussion about surveillance by US warships in the country's maritime territory.
Analysts said such disagreements may continue to arise, even though Sino-US military ties have warmed in recent months.
An 11-member US team comprising defense and diplomatic officials is led by Michele Flournoy, the Department of Defense's undersecretary of policy.
The Chinese side is led by Lieutenant-General Ma Xiaotian, deputy chief of the General Staff of the People's Liberation Army.
The talks took place in the headquarters of the Central Military Commission and will continue today.
Rear-Admiral Yin Changzhi, deputy chief of staff of the People's Liberation Army's Navy, spoke about sea confrontations on behalf of the Chinese delegation.
The Chinese Navy had earlier protested about US surveillance activities, insisting that constant observation by the US in the South China Sea infringed upon the country's territorial rights in its exclusive economic zone and damaged mutual trust between the two militaries.
The US yesterday insisted its surveillance was consistent with its interpretation of international law, but said the US will take action to avoid accidents, the source said.
The two militaries have been caught up in several sea confrontations since March 8, when the USNS Impeccable, a US surveillance ship, was in a standoff with Chinese naval and fishing vessels some 120 km south of China's southern-most province of Hainan.
In the latest incident, also in the South China Sea, a Chinese submarine damaged an underwater sonar array on June 11 being towed behind US destroyer USS John S. McCain.
US defense officials confirmed to the military-background weekly the Navy Times on Monday that the destroyer John S. McCain was tracking the submarine that day.
The Chinese Navy has insisted the US vessels were spying for data related to China’s submarines against US maritime conventions, while the US claimed its acts were within international practices.
"The discussions of the disputes will not upset the US side. Instead, communications on issues of common concerns help the relationships," said Senior Colonel Li Jie, a senior naval esearcher.
"The Sino-US sea confrontations will become more frequent and complicated, so the two nations should from now on learn to seek development while settling disputes," he told China Daily yesterday.
The talks resume this morning and address regional issues, such as the nuclear situation on the Korean Peninsula.
The annual defense talks were originally set for last year but were postponed after China protested against a proposed arms deal to Taiwan endorsed by former US president George W Bush.
(Story by Cui Xiaohuo & Peng Kuang; Video by Cui Xiaohuo & Cao Huan)