Secondly, the patrols went against Washington's public statement that it takes no stand over the territorial claims by six parties in the South China Sea region.

Such patrols, representing a most serious US challenge to China's territorial sovereignty and lawful and legitimate maritime rights and interests, will impact the other claimants of the issue, and encourage their illegal demands.

Actually, China has never stopped its efforts to peacefully solve the disputes. Last Tuesday, senior diplomats from China and the Association of Southeast Asian Nations just consulted on a code of conduct (COC) for the South China Sea, and formulated a list of crucial issues and an outline of the COC.

Thirdly, Washington's allegation to exert so-called rights of freedom of navigation as the international law allows are outright lies. China has never done anything to infringe upon the freedom of navigation in one of the world's busiest sea lanes.

Out of ulterior motives, the US military has been conducting frequent close-in reconnaissance activities against China in the latter's costal waters and Special Economic Zones, which should be blamed.

Chinese Foreign Minister Wang Yi urged the US side on Tuesday "not to act in imprudent way and not to make trouble out of nothing" in the South China Sea. "We advise the US side to think twice before its action," he warned.