India and Vietnam have signed a slew of agreements, including an accord to promote oil exploration in Vietnamese waters, despite Hanoi's long-standing dispute with China over sovereignty of islands in the South China Sea.

The agreement was signed Wednesday in New Delhi after talks between India's Prime Minister Manmohan Singh and the visiting Vietnamese President Truong Tan Sang.

The accord between the Indian and Vietnamese state-owned oil companies includes new investments and the exploration and supply of oil and gas to the two countries.

China has grown more assertive in pressing its claims to much of the South China Sea, aided by a buildup of its navy. New Delhi has downplayed China's recent objections to the Indian company exploring for oil in Vietnamese waters.