Chinese Premier Li Keqiang on Friday called for more international cooperation on sustainable urban development.

China's urbanization is putting people first. This requires harmonious and inclusive urban development, Li said in a congratulatory letter to the World City Day activities in Shanghai.

He said the city is an important platform for human civilization progress and social and economic development.

China is working to realize a rational distribution of cities and towns and coordinated development of big, medium, and small cities and small towns. Only innovate industries can bring about high quality, sustainable urban development, said Li

The premier also called on the international community to strengthen exchanges and cooperation on green cities, smart cities, urban governance, and urban culture.

The idea of World City Day was proposed by the Shanghai Declaration issued at the Shanghai World Expo on 2010, to advocate the idea of better city, better life.