U.S. Secretary of Commerce Penny Pritzker gestures during an audience with a select group of journalists following her address to the American Chamber of Commerce and Filipino businessmen Wednesday, June 4, 2014 at the financial district of Makati city east of Manila, Philippines.

On Wednesday, Philippine officials pressed for China to join the arbitration process as a peaceful solution to the long-raging territorial disputes, which have flared in recent years.

"Arbitration is a peaceful, open and friendly resolution mechanism that offers a durable solution to the disputes," Department of Foreign Affairs spokesman Charles Jose told reporters in Manila.

The tribunal issued a statement Tuesday giving China until Dec. 15 to submit written arguments and evidence against the Philippine complaint, which questioned the validity of China's so-called "nine-dash" territorial claim. That refers to a rough demarcation on official Chinese maps that envelops virtually the entire South China Sea.

Aside from China and the Philippines, Brunei, Malaysia, Taiwan and Vietnam claim overlapping parts of the South China Sea, with Beijing saying it has sovereignty over virtually all of the resource-rich waters. China's disputes with the Philippines and Vietnam have worsened recently, especially after it deployed an oil rig early last month in waters also claimed by Hanoi, sparking violent anti-China protests in Vietnam.

There have been fears the territorial conflicts, including a dispute between Japan and China in the East China Sea, could spark Asia's next armed conflict, although analysts say a major fight is unlikely given that major instability could shatter the region's bullish economies.

Beijing's moves in the disputed waters, which straddle one of the world's busiest sea lanes, were "dangerous conduct and intimidation" that ratchets tension and could undermine the economically vibrant region, said U.S. Secretary of Commerce Penny Pritzker, who was visiting Manila with American business executives.

China has warned the U.S. to stop meddling.

After filing its complaint early last year, the Philippines submitted written arguments and evidence against China's claims on March 30.

The Chinese government notified the five-person tribunal last month that it does not accept the arbitration process, but the tribunal has suggested it would continue hearing the Philippine complaint even without China's involvement.

Any ruling by the Arbitral Tribunal, which operates under the intergovernmental Permanent Court of Arbitration in the Hague, would likely be ignored by China but it will deliver a blow to its image as an emerging global power.