BEIJING, May 26  -- A spokesman for China's Foreign Ministry on Monday refuted Vietnamese comments on the sovereignty of the Xisha Islands, vowing determination to safeguard national sovereignty and territorial integrity.

Qin Gang said the information offered by the Vietnamese side at a press briefing in Hanoi last Friday was ridiculous.

"Their comments showed the country's falsification of history, denial of truth, inconsistency and treachery," Qin said, arguing that Vietnam has little international credibility.

He cited historical evidence to show the Xisha Islands have been China's inherent territory since ancient times.

"China was the first country to discover, develop, name and govern the Xisha Islands," while Chinese people are indisputable owners of the islands, said the spokesman.

According to Qin, the Chinese people discovered the Xisha Islands when they cruised to them during the Han Dynasty (206 BC-220 AD). Since then, lots of Chinese have traveled there for business.

Historical documents show Chinese fished and traded around the Xisha Islands during the Tang (618-907) and Song (960-1279) dynasties, which serves as proof for China's jurisdiction of the area, he said.

During China's Yuan Dynasty in the 13th century, astronomer Guo Shoujing set up an observatory on the Xisha Islands, Qin added.

Vietnam appeared to acknowledge and respect China's sovereignty over the islands before the mid 1970s. In 1956, a senior official of the Vietnamese Foreign Ministry told a charge d'affaires of the Chinese Embassy in Vietnam that the Xisha Islands were part of the Chinese territory, according to the spokesman.

In 1958, China announced it had set 12 nautical miles as the width of its territorial sea and the Xisha Islands were included. Ten days after that, then Vietnamese Prime Minister Pham Van Dong told then Chinese Premier Zhou Enlai that the Vietnamese government admitted the truth of and respected China's statement on its territorial sea, he said.

"For a long period of time, whether in Vietnamese official documents, maps or textbooks, the country admitted the Xisha Islands were part of China and that China had sovereignty of the area," Qin continued.

"However, after 1975, Vietnam breached its previous commitments and claimed sovereignty of the Xisha Islands."

He said the Chinese government and people are determined to safeguard national sovereignty and territorial integrity.