"Russia has been the most important participant in Iran's nuclear program and it will continue under the current agreement to be Iran's major nuclear partner," Zarif told Russia's Channel 1 television.
Energy sector and the fight against terrorism are key areas for cooperation between Iran and Russia, Zarif added.
"In oil and gas cooperation, Iran and Russia share common interest, maintaining stability in global market prices," Zarif told Russia's Channel 1 television, adding that the two countries are also strategic partners in the region against terrorism and extremism.
Sanctions relief for Iran will boost cooperation between Russia and the Islamic Republic, which have always been strategic partners, the Iran's foreign minister said.
"Once the sanctions are lifted, we will concentrate on working with our friends, with Russians, who are not only neighbors, but a strategic partner."