PHNOM PENH - Cambodian Prime Minister Samdech Techo Hun Sen said on Monday that the country will not support an arbitral tribunal's upcoming decision over the South China Sea issue and called on all parties concerned in the disputes to resolve their differences through bilateral negotiations.

In 2013, the Philippines unilaterally filed compulsory arbitration against China at the Permanent Court of Arbitration in The Hague with respect to the two sides' disputes in the South China Sea.

Speaking at a graduation ceremony here, the prime minister said over a month ago, the ambassador of a country outside the ASEAN region had tried to lobby Cambodia and other ASEAN countries to support the tribunal's upcoming decision over the South China Sea.

Hun Sen said that the country's ambassador to Cambodia proposed to him that the Association of Southeast Asian Nations (ASEAN) should have one voice or statement in support of the arbitral tribunal's decision, which will be issued in the upcoming period.

The prime minister said that the tribunal's upcoming decision is "politically motivated" and Cambodia will not support the decision.

"I would like to declare Cambodia's stance that Cambodia will not issue any joint statement in support of the arbitral tribunal's decision," he said. "Cambodia will have its own statement."

In the mid-1990s, China and the Philippines reached a clear agreement on settling their disputes in the South China Sea through negotiation. This has been reaffirmed in many other bilateral documents since then, including the joint statement the two countries issued in September 2011.

China maintains that the tribunal handling the arbitration proceedings has no jurisdiction over the case, which is in essence about territorial sovereignty and maritime delimitation.

Territorial issues are beyond the scope of the UN Convention on the Law of the Sea (UNCLOS), and China has excluded maritime delimitation from compulsory arbitration in a declaration it made in 2006 in accordance with Article 298 of UNCLOS. Therefore, China has made it clear it will not accept or get involved in those proceedings.

The Chinese Ministry of Foreign Affairs said in a statement issued on June 8 that China has all along stood for peacefully settling territorial and maritime delimitation disputes through negotiations with states directly concerned on the basis of respecting historical facts and in accordance with the international law.

On issues concerning territorial sovereignty and maritime delimitation, China never accepts any recourse to third party settlement, or any means of dispute settlement that is imposed on it, the statement said.