German Chancellor Angela Merkel declared that lack of progress on Iranian nuclear program negotiations might lead to imposing new sanctions in energy sector against Tehran, Ria Novosti reports.

U.S. and a number of Western countries accuse Iran of using atom for peace project to develop a nuclear weapon. United Nations Security Council (UNSC) already passed five resolutions and imposed sanctions against Iran demanding to renounce uranium enrichment. However, Tehran denies all charges, declaring the programs are aimed exceptionally at peaceful uses, namely to supply the country with electricity.
In April Iranian mediators (Germany, China, U.S., Great Britain and Russia) offered Iran to get back to the negotiating table to discuss its nuclear program. Besides, at a summit in July, G8 leaders called Iran to do so till September, as they intend to discuss the issue in the course of the next summit meeting in Pittsburgh, U.S., September 24-25.