German Foreign Minister Guido Westerwelle hailed the agreement on Iran's nuclear program reached earlier on Sunday in Geneva as "a turning point" and a major step to come closer to the goal of preventing a nuclear-armed Iran.

The foreign minister made the remarks in Geneva after the announcement of the first-step agreement on Iran's nuclear program. He went to Geneva on Saturday and joined ministers from Britain, China, France, Russia and the United States in the latest round of the nuclear talks with Iran.

According to a joint statement announced by EU foreign policy chief Catherine Ashton, an agreement was reached on a joint plan of action which sets out an approach towards reaching a long-term comprehensive solution on Iran's nuclear program.

Westerwelle described the agreement with Iran as a "turning point" and a significant step closer to the goal of preventing a nuclear-armed Iran. He added that it was the first time a political agreement has been reached on the first substantial steps, despite difficulties and confrontation in the past ten years of the nuclear negotiations.

"We must use the next few months to build mutual trust," he said. "The decisive factors are a transparent and verifiable implementation of the agreements, and rapid continuation of negotiations with a view to a final solution. We are ready for these and we expect the same from the Iranian leadership."