China and Vietnam have agreed to set up a hotline to resolve disputes in the South China Sea, where clashes between fishermen have stoked tensions between the countries, state media reported Thursday.

The agreement was signed by agricultural authorities from Beijing and Hanoi on Wednesday, the state-run China Daily reported, amid a visit to China by Vietnamese President Truong Tan Sang.

"With the establishment of the fishery hotline, each side should be informed of any detainment or treatment by the other side involving fishermen or fishing boats within 48 hours," the paper quoted Wang Ying, a senor official at China's ministry of agriculture, as saying.

China claims virtually the entire South China Sea, which is a key shipping route thought to contain rich energy deposits, based on a map published in the 1940s, but Vietnam and other Southeast Asian countries also claim some areas.

The dispute between China and Vietnam flares up periodically, most recently last month when Vietnam accused China of firing on a fishing boat in its waters.

The agreement came as Vietnam's leader met President Xi Jinping in Beijing. The two nations signed agreements in areas including defence, economy and public diplomacy, state-media said.

Xi reiterated China's position that territorial issues be resolved through bilateral talks, state-media reported.

China has blocked attempts by neighbouring countries to use the Association of Southeast Asian Nations (ASEAN) forum to discuss the ownership of the South China Sea.

"China and Vietnam should make a decision to direct and push forward on seeking a political solution to the South China Sea issue in line with taking responsibilities for history and people," Xi said, as quoted by the official Xinhua news agency.

"We should proceed from the Chinese-Vietnamese friendship and the development of both countries, so the issue does not affect bilateral ties," said Xi during talks with Vietnamese President Truong Tan Sang in Beijing.

Sang told Xi that Vietnam is willing to approach the issue through friendly consultations, according to Xinhua.

Competing claims in the South China Sea have for decades made it one of Asia's potential flashpoints for military conflict. China and Vietnam fought battles in 1974 and 1988 for control of islands that left dozens of soldiers dead.

They also fought a brief, yet bloody, border war in 1979.

Tensions over sea claims have risen again in recent years with both Vietnam and the Philippines accusing China of becoming increasingly aggressive in staking its claim.