Negotiations into a free trade agreement between China, Japan and South Korea hit a snag due to sensitive issues caused by "differences in levels of economic development", Shen Danyang, spokesman for the Ministry of Commerce, said on Wednesday.

The second round of talks into a trilateral agreement was held from July 30 to Aug 2 in Shanghai. Shen said that Japan and South Korea concentrated on very broad issues, including the environment, labor, grain safety, information technology, e-commerce, business.

No other details about the talks were released.

The third round of talks will be held in Japan at the end of this year and Shen urged a more flexible approach to achieve mutually beneficial results.