"As Foreign Minister Wang Yi has said, the Philippines' action of forwarding the arbitration case is unlawful, unfaithful and unreasonable," Foreign Ministry Spokesperson Hua Chunying told a media briefing.
"Its stubbornness is clearly the result of behind-the- scenes instigation and political maneuvering. China is surely not going to humour such a political farce," she said.
Hua was reacting to comments by Daniel Russel, top US diplomat for East Asia that the upcoming ruling by an international tribunal on the arbitration case brought by the Philippines would be a critical moment for the "rules-based" future of the region.
China claims the whole of South China Sea and boycotts the UNCLOS arbitration tribunal questioning its authority, saying it will not recognise the tribunal's decision.
Besides the Philippines, Vietnam, Malaysia, Brunei and Taiwan have counter claims over the resource-rich South China Sea.
Regarding activity by Chinese Coast Guard vessels near Huangyan Island, Hua said China had to strengthen management in the waters to safeguard its sovereignty as well as the local stability and order as Philippine fishing boats were engaged in illegal activities in the region recently.
Such actions "brazenly defy Chinese law enforcement" and "severely endanger the stability and order in the waters of Huangyan Island. Therefore, China had no choice but to strengthen management in the waters of the island," she said.
