China opposes any unilateral energy exploration and development activities in the disputed areas in the South China Sea, the foreign ministry said on Tuesday. The statement came in response to remarks by the Indian navy chief that its navy is prepared to deploy vessels to the sea to defend the South Asian country's economic interests there.

"China opposes any unilateral oil and gas exploration activities in disputed areas in the South China Sea and hopes relevant countries respect China's sovereignty and national interests, as well as the efforts of countries within the region to resolve disputes through bilateral negotiations," Ministry of Foreign Affairs spokesman Hong Lei said.

Hong's remarks came after Indian navy chief Admiral D.K. Joshi said on Monday that Indian warships would sail to the South China Sea to protect its economic interests and freedom of navigation.

India is not a direct claimant of disputed islands in the South China Sea, but a deal signed by the Indian state-run explorer Oil and Natural Gas Corp (ONGC) and Vietnam in October last year to explore the oil and gas block in the disputed waters has sparked a diplomatic row between Beijing and New Delhi.

"The close historical and religious ties between India and Southeast Asian nations give India the advantage in asserting its role in the region," said Zhuang Guotu, head of the Center for Southeast Asian Studies at Xiamen University.

"When the requirement is there, for example, in situations where our country's interests are involved, for example ONGC ... we will be required to go there and we are prepared for that," Joshi said in comments made a day ahead of Indian Navy Day.

He described the modernization of China's navy as "truly impressive" and acknowledged that it was a source of major concern for India, Reuters reported.

The Indian navy chief made his remarks as Indian National Security Adviser Shiv Shankar Menon was engaged in a string of intimate meetings top with Chinese leaders speaking highly of China-India cooperation.

In his Tuesday meeting with Wu Bangguo, chairman of the Standing Committee of the National People's Congress, Menon underscored India's commitment to developing a strategic cooperative partnership with China that is oriented toward peace and prosperity, according to a Xinhua report.

"The real threat posed by India to China is the military cooperation between India and Vietnam. Moreover, India is now controlling several Indian Ocean islands at the entrance of the Malacca Strait, an international energy channel that sees 80 percent of Chinese oil imports passing by every year," said Du Jifeng, an Asia-Pacific issues researcher at the Chinese Academy of Social Sciences.

"As for China, India poses far less of a threat than the US and Japan, because what India can offer to Southeast Asian nations is much less than what the US and Japan can offer," Zhuang added.