A German diplomat said Wednesday that a joint offer may come into being when the UN Security Council's five permanent members and Germany in Vienna met on Thursday to discuss Iran's nuclear crisis.

"(It is) a decisive phase to show Iran an alternative," said Martin Jaeger, chief spokesman for the Foreign Office.

But he declined to give any details about the possible offer.

"We are going into these talks with a certain amount of optimism even though they will not be easy," Jaeger said.

Foreign ministers from France, Britain, Russia, the United States and Germany, as well as a deputy foreign minister from China, will attend the Vienna meeting.

The six countries have failed to clinch an agreement on a common stance to Iran on whether to impose UN sanctions.

Iran began to resume its uranium enrichment program in the beginning of the year and has insisted its nuclear research is for civilian use. But the West suspected it of being aimed at producing nuclear weapons.

Source: Xinhua