Beijing has a crucial role to play in international climate talks being held in Paris in December, French Prime Minister Manuel Valls told Chinese state media Wednesday, saying it was the key issue up for discussion between the two countries.

"2015 will be a crucial year with the COP21 conference being held in Paris, during which a strong and lasting accord must be agreed to address the environmental emergency," Valls told the official Xinhua news agency on the eve of a three-day visit to China.

"By committing to reducing greenhouse gas emissions last November, China has already taken the first step," he added in comments made available to AFP.

Valls said an ambitious agreement to help secure the future of the planet would be signed at the end of the conference, seeking to limit global warming to two degrees Celsius (3.6 degrees Fahrenheit) over pre-industrial levels.

The issue of "green growth" is among the key issues to be tackled in the Franco-Chinese partnership, Valls added, raising questions over how to achieve "sustainable urbanism" and deal with ageing populations.

"In these areas, France has an expertise and knowledge that can be of use in current developments taking place in China," the prime minister added.

On the economic front, Valls said France and China both stand to gain from encouraging mutual investment.

"France is, more than ever, open to China, to its investors, students and tourists," he added, saying that the country aims to host "five million travellers from China by 2020" and 50,000 students in "the coming years".