"This is absolutely not topical," he told RTL radio when asked about the possibility of military strikes against Iran.

"We have always been in favor of a negotiated solution," he said.

Iranian President Mahmoud Ahmadinejad declared on Tuesday that Iran "has joined the club of nuclear countries" by successfully producing enriched uranium for the first time.

Despite the UN Security Council's calling on Iran to suspend all nuclear enrichment activities, Iran has remained defiant, maintaining that its aims are entirely peaceful.

The U.S. government insisted its priority was to seek a diplomatic solution to the nuclear dispute with Iran, but did not deny that it has been stepping up military planning.