German Foreign Minister Guido Westerwelle hailed reaching a political agreement with Iran on curbing its nuclear activities as "a major step" in 10 years of negotiations and urged for further steps towards a comprehensive solution.
"The Geneva agreement marks a turning point," Westerwelle said on Sunday in Geneva.
"With this major step we have come closer to our goal of preventing a a nuclear-armed Iran."
Germany has been among the group of nations that negotiated the nuclear deal with Iran alongside the five permanent members of the UN Security Council.
Westerwelle made an unscheduled visit to Geneva on Saturday and joined ministers of other world powers who struggled to nail down the landmark nuclear deal with Iran.
According to the agreement Iran will temporarily curb its nuclear program, initially for six months, in return for relief from sanctions.
'Time to build mutual trust'
The German foreign minister underlined that despite various difficulties and at times confrontation with Iran in the past ten years of the nuclear negotiations, for the first time a political agreement has been reached on the first substantial steps.
"We should use the next months to build mutual trust," Westerwelle said on Sunday.
"The decisive factors would be a transparent and verifiable implementation of the agreements and the quick progress in negotiations with a view towards reaching a final solution," he stressed.
"We are ready for these and we expect the same from the Iranian leadership."