"China hopes to give dialogue every opportunity, France understands this," Sarkozy said at a joint press briefing with Chinese president Hu Jintao in the Chinese capital.
"The whole question is to examine at what point the absence of constructive dialogue, must lead to sanctions in order to enhance constructive dialogue. Everyone is convinced that moment is approaching."
Sarkozy said he told Hu that the progression by Iran toward "nuclear armament" could harm world stability.
Neither Hu nor Sarkozy took questions.
(Reporting by Emmanuel Jarry, writing by Lucy Hornby)