QINGDAO (REUTERS) - More than 20 countries with interests in the western Pacific signed up to a framework maritime communication deal on Tuesday in what could a step towards ensuring that miscommunication between naval vessels does not develop into a conflict.

Naval officers from China and the United States told Reuters the document was not meant to directly address problems, including territorial issues, pitting China against several of its neighbours in the East and South China Seas.

But incidents in those waters have raised fears of an accidental clash, which could escalate into a broader conflict.

The United States wants clearer operational communications with the growing Chinese fleet, arrangements in part hampereed by different interpretations of what operations are acceptable in international waters, US naval officers have said.

The risks of a mishap were highlighted in December when the US guided missile cruiser USS Cowpens had to take evasive action in the South China Sea to avoid hitting a warship supporting China's first aircraft carrier, the Liaoning.

China's increasingly assertive navy, which has modernised quickly in the past decade, has sparked nervousness from other countries in the region - particularly Japan.

More than 20 countries with strategic interests in the Western Pacific region unanimously agreed to the framework, including China, Japan, the Philippines and Malaysia.

The agreement took place at a meeting of the Western Pacific Naval Symposium in the eastern Chinese coastal city of Qingdao.

A late draft of the non-binding document, obtained by Reuters, is essentially a handbook for manoeuvres and communication when naval ships and aircraft from the signing countries encounter each other unexpectedly.

Navies are told to fire off flares in green, yellow and red in different situations and given a list of English-language terms.

"The document is not legally binding, rather, it's a coordinated means of communication to maximise safety at sea," the draft says.

The final version has not been publicly released, but a naval official privy to the discussions said the language in the draft was close to what had been formally agreed upon.

The document defines "unplanned encounters" as when vessels from two countries meet "casually or unexpectedly".

On the sidelines of the conference, Xu Hongmeng, vice admiral in the navy of China's People's Liberation Army, said the agreement would have a positive impact on maritime conduct, emphasising that it was voluntary.

But he added that it would have no impact on conduct in the disputed waters of the East and South China Seas.

"You can't say that it's related to the issues in the South and East China Sea - this is about the navies of many countries," Xu said. "This will not influence those issues."

Beijing's increasingly assertive stance on maritime security in what it sees as its territorial waters has stoked concerns in the region, particularly as its military and civilian ships increase patrols in disputed areas.

Chinese and Japanese ships routinely shadow each other near a chain of disputed islets in the East China Sea, a development which analysts have said raises the risk of a conflict.

"The number of communications between the Japanese and Chinese defence forces is small," said Japanese Navy Captain Masahiro Sakurai, without elaborating.

The United States has long-standing defence treaties with Japan and the Philippines, raising the prospect of Washington being drawn into a potential conflict if a collision sparks wider tensions.

It is unclear whether this agreement clears up differences rooted in different interpretations of military activity.

Beijing has objected, for example, to US surveillance operations near its coast, even if Washington insists they are in international waters.

Separately, China and the 10 countries of Asean are negotiating a binding Code of Conduct to ease tensions in the South China Sea before territorial disputes can be resolved.

The code extends far beyond improved communications, seeking to halt military exercises in disputed waters and limit construction on empty reefs and islands, diplomats say.