Wen made the appeal during a meeting with Congolese President Denis Sassou on the sidelines of the UN Conference on Sustainable Development, known as the Rio+20 summit, which started here Wednesday afternoon.

"The two countries have always supported and helped each other since they established diplomatic relations 48 years ago," Wen said.

Noting that recent years have seen an remarkable expansion in the scale of bilateral cooperation, Wen said the Republic of Congo is now an important economic and trade partner of China in central Africa.

China, Wen said, values its traditional friendship with Congo and is ready to further promote all-round and multi-tier exchanges and cooperation.

Meanwhile, Wen pledged that China will enhance solidarity and cooperation with African countries, support a more united and interdependent Africa, and help African countries realize sustainable development so as to lift the new China-Africa strategic partnership to a higher level.

For his part, Sassou said his people have always held deep friendly feelings toward the Chinese people and are grateful for the support offered by China.

In recent years, the relationship between the two countries has made headway, he said, adding that a series of cooperative projects have implemented, bringing real benefits to the Congolese.