China Tuesday stressed the importance of diplomacy in resolving the Iran nuclear crisis, following the UN Security Council resolution demanding Iran halt nuclear activities by August 31.

"China hopes the… resolution on Iran's nuclear issue would serve the ongoing diplomatic efforts to settle the standoff," the official Xinhua news agency quoted foreign ministry spokesman Liu Jianchao as saying.

"China calls on all parties concerned to keep calm and exercise restraint, and continue to push forward (for an) early resumption of negotiations."

The Security Council on Monday passed the resolution 14-1, with Qatar the lone dissenting voice, to order Iran to halt its nuclear activities by August 31 or face the threat of sanctions.

The resolution expressed "serious concern" at Iran's refusal to comply with International Atomic Energy Agency orders to halt uranium enrichment and other work that could help build a nuclear bomb.

The resolution was welcomed by the United States and its allies, but decried as "destructive and totally unwarranted" by Iran's UN ambassador.

While China and Russia voted for the resolution on Monday, they have consistently advocated a softer line against Iran than the United States, particularly on the issue of potential sanctions.