MUNICH — Iran’s foreign minister, Mohammad Javad Zarif, was assailed by hard-liners in Tehran last month for talking a widely photographed walk in Geneva with Secretary of State John Kerry during a break in their talks on Iran’s nuclear program.

Conservative Iranian lawmakers even signed a petition asking Mr. Zarif to appear before Parliament to provide an explanation. “There is no conceivable ground for intimacy between the foreign ministers of Iran and America,” said the petition, Reuters reported at the time.

On Friday, Mr. Zarif, who has a well-deserved reputation as a smooth-talking diplomat who likes to banter with Western reporters, was much less visible.

Mr. Zarif and his team met with Mr. Kerry and his aides for more than an hour on the sidelines of a security conference here. Helga Schmid, a senior European Union diplomat, also attended the session.