HANOI - Vietnam's National Museum of History displayed on Wednesday a map donated by a local historian that he said proved China had no claim to disputed islands in the South China Sea.
The map was donated by Dr. Mai Ngoc Hong who said it was a 1904 Qing dynasty map of Chinese territories that did not include the disputed Spratley and Paracel Islands.
"I have one wish that this map is known not only to the Vietnamese but also to Chinese people and scientists. The legality of this map clearly shows Vietnam's sovereignty over the two islands. There is no arguing about that," he said adding he spent a month's salary to pay for the map.
Beijing, which lays claim to the whole South China Sea, recently upset Hanoi after the government-backed China National Offshore Oil Corporation (CNOOC) said it was seeking bids for oil exploration in what Hanoi deems Vietnamese waters, while Hanoi increased tensions last month by adopting a law claiming sovereignty over the Paracel and Spratly Islands.
Beijing's claims have recently sparked protests in Hanoi, despite the authorities rarely allowing public demonstrations.
The 74-year-old Hong said the Vietnamese people were strong.
"The Vietnamese are a special race. We are like a hard constrained spring. Use force on it and it will coil, and watch out when it does," he said.
Meanwhile, Indonesian Foreign Minister Marty Natalegawa returned to Vietnam on Wednesday for the second time in a week to meet with his counterpart Pham Binh Minh to try to find a diplomatic solution to the row.
The 10-nation group Association of Southeast Asian Nations (ASEAN) could not agree a concluding joint statement at a ministerial meeting earlier this month in Cambodia, due to discord over how to address China's increasingly assertive role in the strategic waters.
One ASEAN diplomat accused China of buying the loyalty of Cambodia and some other states with economic largesse.
Natalegawa has been shuttling back and forth between member countries in an attempt to bring about some sort of consensus. Indonesia, which is neutral in the issue has been tasked with drawing up a code of conduct for the area to prevent any acts of brinkmanship spilling over into the conflict.
Natalegawa said he hoped he could count on Vietnam's cooperation.
"Whatever are the issues, including the issues to do with the East Sea or the South China Sea, I am sure I can continue to rely on Vietnam to be a strong partner to be able to ensure the continued centrality and continued prominent role of ASEAN in the region's architecture building," said Natalegawa.
The Philippines, Brunei and Taiwan also lay claims in the South China Sea that includes sea lanes that carry an annual $5 trillion in ship-borne trade, particularly if it raises the prospect of U.S. intervention after the U.S. announced its "pivot towards Asia" strategy.