China on Wednesday rejected a Hague-based arbitration tribunal's ruling giving it six months to respond to a legal claim by the Philippines over disputed waters in the South China Sea.

China's stance of not accepting or participating in the arbitration proceedings filed by the Philippines has not changed, Chinese foreign ministry spokesperson Hong Lei said at a regular briefing on Wednesday.

The response came after the tribunal of The Permanent Court of Arbitration in The Hague, the Netherlands, issued a statement on Tuesday, which requires China to submit evidence to defend its territorial claims in the South China Sea before December 15.

The tribunal cited an obligation to assure "each party a full opportunity to be heard and to present its case," according to a Tuesday statement.

The Philippines in March filed a memorandum to the international arbitration under the United Nations Convention on the Law of the Sea (UNCLOS), questioning the validity of China's "nine-dash" territorial claim.

However, experts said that without a bilateral agreement, the UNCLOS has no jurisdiction to interfere in sovereignty issues, which made China's stance reasonable and lawful.

"The international arbitration procedure must be agreed by both parties. If China rejects participating, the arbitration will not work," Ji Qiufeng, a professor of international relations with Nanjing University, told the Global Times.

Ji noted that the international tribunal is most likely to withdraw the Philippines' case.

"It will be a wise decision for the international tribunal as it lacks power to enforce. Even if the tribunal makes a judgment by default, China will not accept its verdict," Ji said. "The tribunal may lose its credibility."

The United States has said it supports the Philippines' arbitration case, which is closely watched by other claimant countries including Vietnam, which said last month it was considering legal action against China after a Chinese oil rig started to operate in waters near the Xisha Islands that Hanoi claims as it territory.

Ji pointed out that Vietnam's legal threat is very likely to depend on the result of the Philippines' case. "As China stands firm against the Manila plea, Hanoi should be aware that the threats would prove in vain."