A group of Japanese business leaders and Chinese Vice Premier Li Keqiang have agreed the two countries will strengthen ties in energy efficiency and environmental protection.

Li expressed willingness to promote studies for an envisaged trilateral free-trade agreement involving South Korea, a Japanese delegation member told reporters after talks Wednesday in Beijing.

The delegation was led by Hiromasa Yonekura, chairman of the Japan Business Federation (Nippon Keidanren), and Fujio Cho, chairman of Toyota Motor Corp.

Cho was quoted as telling Li that Japan's business world is concerned about China's export controls on rare earths used in hybrid electric vehicles, mobile phones and other high-tech products.

Li responded that the Chinese measure stems from concern over potential depletion of the resources and environmental degradation caused by excessive development, according to the delegation member.

He indicated China would accept Japan's proposal for technology cooperation to quell Beijing's concern, according to the delegation member.