Israel's prime minister on Monday called for "crippling sanctions" against Iran over its nuclear program after a meeting with Russia's top officials, whom he praised for showing "an understanding" over the issue.

Russia has generally resisted new sanctions, but has shown increasing frustration over the past week as Iran proceeds with uranium enrichment despite international pressure. Critics say the enrichment is aimed at producing nuclear weapons.

Russian news agencies made no mention of Iran in reports of Russian President Dmitry Medvedev's opening remarks at his meeting with Prime Minister Benjamin Netanyahu.

Israel wants "sanctions, and sanctions that have teeth," Netanyahu said, calling for a blockade on Tehran's energy trade. "The sanctions have to focus on the importing and exporting of fuel."

Netanyahu praised Russian officials for showing "an understanding."

"I can say that Russia definitely understands there is a need to prevent Iran from obtaining nuclear weapons and it understands that steps must be taken," he said. "I trust what I heard from the president of Russia, whose decisions are driven by concerns of regional stability."

Israel is deeply worried about the nuclear program of Iran, which has expanded in defiance of five U.N. Security Council resolutions — and three sets of U.N. sanctions — aimed at pressuring it to freeze enrichment.

Iran's Bushehr atomic energy plant was built by Russia, and the country has worked to keep strong ties with Iran despite concerns that the Bushehr plant would be a stepping stone toward nuclear weapons.

Russia has also caused concern in Israel with its contract to sell S-300 long-range air-defense missiles to Iran, which would significantly boost Iran's defense capability.

None of the missiles have been delivered, Russian officials say, although there have been no public explanations for the delay. Some observers suggest Russia is holding back on the missiles to persuade Iran to back off on its nuclear ambitions.

Netanyahu, who refused to say whether an Israeli military offensive was discussed, remarked there has been a convergence of international opinion on the threat from Tehran.

"There is a growing understanding about the Iranian threat and the need to stop them from developing a nuclear weapon. The gaps between the leading countries is getting smaller and smaller."

Netanyahu made a clandestine visit to Moscow in September after rumors emerged that a hijacked Russian freighter may have been secretly carry S-300s bound for Iran. No details of that visit have been released, although Medvedev later acknowledged it had taken place.

On Monday, Medvedev welcomed Netanyahu and said Russia regards Israel as more than an ordinary partner.

He also noted that 2010 marks the 65th anniversary of the defeat of Nazi Germany and said "it's important not to allow interpretations of what went on at that time."

Russia in recent years has repeatedly taken offense at actions in some former Soviet republics that it regards as disrespectful to the Red Army's fight against the Nazis.