Nikolai Patrushev, head of Russia's national security council, said on Tuesday that actions such as starting to enrich low-enriched uranium up to 20 percent to higher levels itself give rise to "well-grounded" doubts about Iran’s pledge not to pursue nuclear weapons.

Moscow has for years said there was no evidence that Iran was pursuing anything but a civilian nuclear energy program as it claimed.

"There is no doubt that Russia is toughening its position on Iran," Alexander Konovalov, an analyst at the Institute for Strategic Assessments told AFP, calling the comments a "clear indication that Russia is displeased.” He added that Russia will support a new round of sanctions against Iran.

Patrushev also said that Moscow’s patience in trying to seek dialogue with Iran was wearing out. "Political and diplomatic methods are important for regulating, but everything has its limit," Patrushev was quoted as saying Tuesday.

He called for Iran to take part in "open cooperation with the International Atomic Energy Agency."

-AFP/NOW Lebanon