China and France have stepped up their diplomatic rapport after a reconciliation at the G20 Summit in London late last year.

It will reach a high point when French President Nicolas Sarkozy visits China to attend the opening of World Expo in Shanghai in May.

Former French prime minister Jean-Pierre Raffarin hailed the development as a clear sign the two countries have put their previous differences behind them.

"I am glad that all the problems in the past have been cleared up," Raffarin said in Shanghai, where he is leading a drive to promote the investment of small and medium-sized French companies in China.

"I believe that diplomatic relations between France and China are back to normal, thanks to the efforts of both governments," he said.

A highlight of his visit to Shanghai is to preside over the opening ceremony of the "Salon du Chocolat", a showcase of the exquisite French touch in fine chocolate. The show will be held in the Shanghai Exhibition Center between today and Saturday.

Raffarin also met Shanghai Expo officials during his visit to the site and to the French pavilion, which is under construction.

Raffarin has been a keen promoter of Sino-French relations since he was the prime minister of France between 2005 and 2007. He has made more than 30 visits to China to show his firm support for cooperation between the two countries.

His popularity in China has been enhanced by his personal blog on ifeng.com, the Chinese website of a Hong Kong television station.

"The meeting between the presidents of France and China will promote Sino-French cooperation on global strategies and the rebuilding of the world financial system," Raffarin wrote in the latest message on his blog in Chinese. "The reconciliation between France and China is especially important to President Nicolas Sarkozy," he wrote.

A string of events, including a meeting of the French president with the Dalai Lama, led to increased tension between China and France. The differences were largely resolved at the meeting between Hu and Sarkozy in London before the opening of the G20 Summit.

French Prime Minister Francois Fillon's visit to China in December also enhanced cooperation in science and technology, information, water conservation and culture.

Yet the view held by the French government towards carbon tariffs has raised concern in China that Paris is resorting to trade protectionism.

Raffarin disagreed. "The carbon tariffs are purely for the protection of the global environment and support the wider use of renewable energy. I'm sure that France will never return to protectionism," he said.