DUBAI: Iranian officials said Russia's demands at talks on Iran's nuclear deal in Vienna are "not constructive", Iran's semi-official Tasnim news agency reported on Monday.

Russia's "interference" was aimed at securing its own interests, the agency cited unidentified Iranian officials as saying.

Russia has demanded a US guarantee that the sanctions it faces over the Ukraine conflict would not hurt its trade with Iran.

The demand could be a stumbling block in the talks.

By postponing the revival of the agreement between Iran and the Western powers, and delaying Iran's return to the oil market, Russia was seeking to raise crude prices and increase its own energy revenue, the news agency said, without citing a source for that assessment.