German Foreign Minister Frank-Walter Steinmeier said nuclear talks between Iran and the major powers are entering a "very decisive period".
"But we're not at the endpoint. The basic points need to be translated into a comprehensive negotiating text and that's not easy as negotiating in detail has created a few hindrances," he told journalists on Monday in Luxembourg, Reuters reported.
"We must hope that the Iranians move on decisive points and that we come to a close," he said.
French Foreign Minister Laurent Fabius also said on the same day Paris wants a robust nuclear agreement with Iran that should include a strong verification mechanism to check Tehran's compliance with any deal.
Fabius spoke after meeting Foreign Minister Mohammad Javad Zarif, who was in Luxembourg for talks with European ministers before negotiators head to Vienna this week for what could be the final stage of talks on a comprehensive deal to resolve the 12-year dispute over Tehran's nuclear program.
Iran and the P5+1 (the United States, France, Britain, Russia, China and Germany) are nearing a June 30 deadline to clinch the deal which would place restrictions on Iran's nuclear activities for specified durations in exchange for relief from sanctions.
"France wants an agreement, but a strong agreement, not a bad agreement," Fabius said in a brief statement to reporters after an hour of talks with Zarif.
Such an accord would include a time limit on Iran's nuclear research and production capabilities and an advanced regime to verify Iran's compliance with the agreement, including "if necessary" at military sites, he said.
It should also include the automatic return of sanctions if Iran violates its commitments, Fabius said.
"All that is important both for regional security and for action against nuclear proliferation," he said.
Iran denies its nuclear program may have any military objectives, saying the work is solely for peaceful purposes. Tehran has also ruled out inspection of its military facilities under any accord.
Earlier, British Foreign Secretary Philip Hammond said Iran would need to show more flexibility to reach a nuclear deal, suggesting the talks might go on beyond the June 30 deadline.
"There will need to be some more flexibility shown by our Iranian partners if we are going to reach a deal," Hammond said.
