Russia and China will "definitely not" approve the use of force against Iran over its nuclear program, Russian Foreign Minister Sergei Lavrov said after meeting with China's leaders.

Russian Foreign Minister Sergei Lavrov (L) meets Chinese President Hu Jintao in Beijing. Lavrov said Russia and China will "definitely not" approve the use of force against Iran over its nuclear program. [AFP]

"Russia and China will definitely not vote for the use of force to resolve this issue," Lavrov said through a translator after meeting with his Chinese counterpart, Li Zhaoxing, and President Hu Jintao.

"We believe we shouldn't isolate Iran or increase pressure. This will not only not reduce the possibility of proliferation of weapons of mass destruction, it will have the opposite effect."

However Lavrov also said Russia believed Iran needed to do more to cooperate with the United Nations nuclear watchdog, the International Atomic Energy Agency.

"Iran at the moment has not completely replied to and given explanations on the questions raised by the IAEA investigation," Lavrov said.

"We regret this very much. We hope the Iran side will give a reply at an early date."

The IAEA has been investigating Iran since 2003 and says it is not yet able to certify that the Iranian nuclear program is strictly peaceful.

Iran says its nuclear program is a peaceful drive to generate electricity but the United States and other Western nations say it is a cover for the secret development of atomic weapons.