China said on Tuesday that it wanted to counter Vietnam's "slander" to the world about what was happening in disputed areas of the South China Sea, after Beijing asked the United Nations to circulate documents outlining its position.
A senior U.S. diplomat called on China to provide evidence to back up its claim to 90 percent of the sea, believed to be rich in energy and minerals.
And the Philippines, embroiled in disputes with China over its claims to parts of the sea, defended a weekend get together on the disputed Spratly Islands of Philippine and Vietnamese servicemen and said another gathering would be staged next year.
Tensions have been running particularly high between China and Vietnam, focusing on China's positioning of an oil rig near another disputed archipelago, the Paracel Islands, which has lead to rammings at sea and anti-Chinese violence in Vietnam.
China and Vietnam have traded accusations about the behaviour of their ships, including the use of water cannon and intentional rammings.
Chinese state news agency Xinhua said that Wang Min, China's deputy permanent representative to the United Nations, had asked U.N. Secretary-General Ban Ki-moon in a letter to circulate documents outlining China's position to all U.N. member states.
China, he said, sought to "tell the international community the truth and set straight their understanding on the issue".
Asked about the move, foreign ministry spokeswoman Hua Chunying said Vietnam had been stepping up its harassment at sea and trying to vilify China on the international stage.
"On the one hand, they have been increasing their damaging and harassing activities on the scene, while internationally everyone has seen they have been unbridled in starting rumours and spreading slander, unreasonably criticising China," she told a daily news briefing.
China, she said, had to explain the "real situation" to be clear "about Vietnam's real aim in wantonly hyping things up".
A policy document released at the weekend accused Vietnam of ramming its ships more than 1,000 times in the oil rig dispute, though it said Beijing wanted good relations with its neighbour.
The spat is the most serious deterioration of relations between the Communist states and traditional rivals since a brief war in 1979 following Vietnam's invasion of Cambodia.
U.S. APPEALS TO BEIJING
The U.S. Assistant Secretary of State for East Asia and the Pacific, Daniel Russel, urged China to seize the "significant opportunity" of a call from an international court last week for evidence to back up its claims.
"This ... opens the door to the removal of some ambiguity regarding China's claim that has helped fuel tension and uncertainty in the region," Russel said in a telephone briefing with reporters in Hong Kong.
Russel said he had raised the issue with regional officials at a meeting in Myanmar of the 10-nation Association of South East Asian Nations (ASEAN).
A judges' panel at the Permanent Court of Arbitration in The Hague said last week that it was giving China six months to respond to a case filed by the Philippines in March. China's Foreign Ministry last week restated its refusal to participate.
China rejects any international solution to the territorial disputes and calls for individual talks with claimant countries.
The Philippines, Malaysia and Brunei each claim some of the Spratlys, while China, Taiwan and Vietnam claim the whole chain.
Servicemen from the Philippines and Vietnam staged a get-together last weekend on a Vietnamese-administered part of the archipelago, playing soccer and volleyball and drinking beer. China denounced the gathering as a "clumsy farce".
A Philippine navy spokesman told reporters Manila would host a get-together next year on a Philippine-run island, with all claimant countries invited.
"If the end is to maintain good relations and amity with a neighbouring nation and sports is one of the means to attain it, then the navy will have to pursue it," Col. Edgard Arevalo said.
"The least of our intentions is to pick quarrels with anyone. Definitely, it's not meant to pick on China." (Additional reporting by Rosemarie Francisco in Manila and Greg Torode in Hong Kong; Editing by Ron Popeski)
By Ben Blanchard