PHNOM PENH, June 28 -- Ruling Cambodian People's Party (CPP) President and Prime Minister Samdech Techo Hun Sen announced on Tuesday that the CPP would not back the arbitration court's upcoming decision over the South China Sea issue, saying that the party saw the upcoming decision as "the worst political collusion in the framework of international politics".

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. The Chinese government has reiterated its non-acceptance and non-participation stance in the case.

"The CPP does not support, and more so is against, any possible declaration by ASEAN to support decision of the Permanent Court of Arbitration in relation to the South China Sea disputes, which some countries outside the region have wire-pulled and pressured ASEAN members even before the court reaches a decision," Hun Sen said in a speech during the CPP's 65th founding anniversary in Phnom Penh.

"The CPP foresees this issue, and views it the worst political collusion in the framework of international politics, the result of which would lead to division among ASEAN members themselves and between ASEAN and China," he said.

The prime minister warned that efforts of some countries outside the region to mobilize forces against China would bring negative impacts on ASEAN and peace in the region.

He said the CPP regards the South China Sea issues are matters between countries directly concerned, and not ones between ASEAN and China.

"In this sense, the CPP appeals to every concerned countries to resolve their issues peacefully together," Hun Sen said. "Only countries concerned will be able to resolve this problem. ASEAN is not able to work on behalf of those countries concerned."

He said that there is the ASEAN-China mechanism to resolve issues through the Declaration on the Conduct of Parties in the South China Sea (DOC) signed in Phnom Penh in 2002.

"The CPP calls on all concerned parties to implement justly the spirit of DOC, while ASEAN and China work together to achieve a Code of Conduct in the South China Sea (COC)," the prime minister said.

Meanwhile, he called on countries outside the region to cease their interference on issues of South China Sea.

"The CPP also appeals to concerned countries and those with attention given to South China Sea issues to stop using South China Sea as bargaining tool or hostage in regional and international meetings for the results in recent years have been divisive," he said.

Hun Sen said Cambodia had again, and again, become victim of South China Sea issue because of unjust accusations and expressed hopes that countries unconcerned will not suffer injustice as Cambodia did.

The prime minister also said that ASEAN has so much more works to do besides dealing with the South China Sea issue.