Asia's economy, supported mainly by robust developments in China and India, grew by 8.3 percent in 2006, and the momentum will continue in the coming years, Asian Development Bank (ADB) President Haruhiko Kuroda said in Tokyo on Tuesday.

Developing Asia as a whole achieved a year on year economic growth of 8.3 percent last year, with China and India accounting for 70 percent of that growth, Kuroda said, adding that China's double-digit annual growth of 10.7 percent and India's buoyant expansion of 9.2 percent suggest that high growth is likely to be sustained for some time in the future.

Kuroda made the remarks during a speech at the Foreign Correspondents Club of Japan. He said the fast rise of China and India presents opportunities and challenges also.

"Given their size and economic weight in Asia, as well as their strategic locations, China and India are well positioned to increase their engagement with other regional economies, but the success of these large economies also means that the smaller ones must work even harder to remain competitive," Kuroda said.

"However, ongoing economic, institutional and governance reforms at the national level will help the smaller and less developed economies gain better access to the neighboring economies and the global economy," he added.

He also pointed out that environment conservation is a critical problem challenging Asia.

"Asia's rapid growth has come at a large environmental cost, leaving an unfortunate legacy of polluted cities, degraded forests and farmlands, reduced biodiversity and other problems that must be resolved for growth to be sustainable," Kuroda said, warning that these problems are likely to worsen if Asia does not move to a more sustainable course in terms of energy production and use.

He said ADB will take the opportunity of its 40th board of governors meeting which will be held in Kyoto in May to focus attention on such challenges and obligations to ensure a clearer and healthier future.