BUDAPEST (AFP) -- Russia is optimistic that Iranian negotiators will agree to return to an international protocol limiting Tehran's nuclear activities, Russian President Vladimir Putin said here on Tuesday.

"We are optimists and consider we can come to an agreement with our Iranian interlocutors about returning Iran to the additional protocol," Putin said during a visit to Hungary.

"We can agree also on setting up a joint venture on Russian territory ... for enrichment of uranium for the nuclear industry of Iran," Putin said at a news conference.

Germany is not optimistic that talks between Russia and Iran will result in a deal that will allay international concerns over the Iran’s nuclear program, German Foreign Minister Frank-Walter Steinmeier said also on Tuesday.

"We hope that these talks lead to success," Steinmeier told reporters in Kiev after meeting his Ukrainian counterpart, Boris Tarasyuk.