According to state media, much of the first day of talks was taken up with discussion of recent confrontations between Chinese and US naval vessels in waters that China claims as its own territory.

US officials says China's navy has become increasingly aggressive in its patrols [EPA]
China regards the entire South China Sea as its own - despite competing territorial claims from different Asian nations - and interprets international law as giving it the right to police foreign naval activity there.

In the latest incident earlier this month, a Chinese submarine damaged a sonar array being towed by a US destroyer.

China called that case an accident, but the recent spate of close encounters between the two sides has raised tensions and fuelled concerns that a future clash could escalate into a wider conflict.

US defence officials also fear that China's navy is growing increasing aggressive in its patrols and have called for more contacts on the issue to head off potential dangers.

The state-run China Daily newspaper reported that the topic took up 45 minutes out of the three-hour opening session on Tuesday, although no conclusions were announced.

Freighter tracked

The talks also come as the US navy continues to track a North Korean freighter, the Kang Nam, that according to some reports is carrying weapons including missiles and missile parts bound for Myanmar.

The US is stepping up pressure for Pyongyang for a halt to its nuclear and alleged weapons proliferation activities, in contrast to China which is urging a softer approach in dealing with the North.

Reports say the Kang Dam may be carrying weapons including missiles [AP]
China is North Korea's closest ally and has called for caution by countries tracking alleged North Korean weapons shipments.

The Kang Nam is the first North Korean ship to be monitored under new UN sanctions, authorising UN member states to inspect North Korean sea, air and land cargo.

The resolution, toughening existing sanctions against the North, was adopted in response to the North's latest nuclear test carried out last month.

On Tuesday Qin Gang, spokesman for the Chinese foreign ministry, said that evidence must be put forward by countries tracking the Kang Nam before any move was made to board the ship and check its cargo.

"China will strictly observe the relevant resolution of the Security Council. We believe ship inspections should be enforced according to relevant international and domestic laws, and one should have ample evidence and proper cause," he said.

His comments highlight the divide between China and other powers that have sought a more assertive approach to North Korean ships they suspect may be carrying illicit trade.