Germany is one of three EU nations along with Britain and France in the midst of crucial talks with Iran aimed at finding a long-term solution that would ease international concerns.

"In the view of the German government, there is no alternative to these discussions," spokesman Bela Anda told a press conference.

US President George W. Bush said on Monday that he could not rule out resorting to military action if Iran could not be persuaded to abandon a nuclear energy programme which Washington believes is a cover for developing a bomb.

Iran vehemently denies that it is developing nuclear weapons.

Anda said there was "nothing new" in the fact that the United States reserved the right to use several options to solve the crisis.

"These negotiations are taking place in close cooperation with the United States," he added.

A spokesman for the German foreign ministry said the talks with Iran, though difficult, were "on the right course".