"The German government has been concerned for a long time about the progress of Iran's atomic programme. The content of the (IAEA) report naturally reinforces these worries considerably," Steffen Seibert, spokesman of Chancellor Angela Merkel, was quoted as saying by Xinhua.
He said Tehran must return to the negotiating table, be more transparent about its nuclear activities to the world's powers, including the US, Russia, China, Britain, France and Germany.
Foreign Minister Guido Westerwelle said: "The detailed signs concerning a possible military dimension of the Iranian nuclear programme are alarming."
He said new sanctions would be "inevitable" in case Iran refused talks.
"If Iran continues to refuse serious negotiations about its nuclear programme, new, stricter sanctions will be unavoidable. The route via the most broadly shared sanctions possible is the right one," Westerwelle said.
Published 10 November 2011, 04:32 IST