Vladimir Putin, Russia's president, did not give any reassurance that Russia would check any Iranian intent to acquire nuclear weaponry following a plea from Ehud Olmert, Israel's prime minister, on Wednesday in Moscow.
Although ties between Russia and Israel have warmed dramatically since the Soviet Union collapsed, the two countries are in deep disagreement over how to confront the Iranian nuclear threat.
Israel considers Iran to be its greatest threat.
Israel, like the West, disbelieves Tehran's claims that it is developing energy, and wants its nuclear capabilities to be put in check.
However, Russia continues to build Iran's first nuclear reactor, and has impeded the imposition of UN sanctions on Tehran for refusing to scale back its nuclear ambitions.
"We don't have the privilege to ignore the true intentions of Iran, whose leadership publicly calls for the destruction of the state of Israel," Olmert said at a joint press conference with Putin.
"The entire international community must join ranks to block Iran's intention of arming itself with nuclear weapons.
"I leave this meeting with the sense that President Putin understands better than before the danger that lurks from Iran's direction, should it succeed in realising its objectives of arming itself with nuclear weapons."
Putin remained silent, saying nothing about Iran at the news conference.
Asked afterwards in a briefing with Israeli reporters whether he was disappointed by Putin's silence or had received private assurances, Olmert replied that he was convinced Putin is "very concerned" Iran might acquire nuclear capabilities.
Alexei Malashenko, a Middle East expert at the Moscow Carnegie Centre, said Russia would continue to hold out against imposing sanctions on Tehran, to safeguard its strong commercial interests and independent role in the Middle East.
"Russia will resist until the end. If it backs down and decides to make concessions, it will lose its image in the Muslim world," he said.
Western concerns about Russia's role in the Iranian standoff grew last month after Moscow caved in to Iranian pressure and agreed, by March, to ship nuclear fuel to the atomic power plant it is building in Iran.
Supplies to Hezbollah
Russia's supply of military technology to other countries was another subject Olmert addressed after the meeting. Israel claims that Lebanon-based Hezbollah fighters used Russian missiles against it in summer.
Israel does not accuse Russia of directly supplying Hezbollah, but maintains the arms were sold to Syria and Iran, which sent them on to their Hezbollah proxies.
Russia has denied its missiles reached Hezbollah.
Olmert, in his briefing with the Israeli press, would not say whether the Russians confirmed Israel's claims. But he said he was "satisfied" from his talks with them that they would "do all in their power to take steps so we don't have to worry in the future".