The presidents of Russia and Iran have held talks that Vladimir Putin's spokesman says covered military and nuclear cooperation, as well as the fight against the Islamic State group.

Putin and Iran's Hassan Rouhani met Thursday in the Russian city Ufa, which is hosting a summit of the Shanghai Cooperation Organization in which Iran has observer status.

The Russian president's spokesman, Dmitry Peskov, said Putin noted "positive dynamics" in the ongoing Vienna talks about a final agreement on Iran's nuclear program, according to Russian news agencies.

Peskov declined to say whether the talks touched on the delivery of S-300 advanced air-defense systems to Iran. After a framework agreement on Iran's nuclear program was reached this spring, Putin lifted Russia's suspension on sending the S-300s, but no deliveries have been reported.