MOSCOW — Prime Minister Olmert of Israel made a surprise trip to Moscow today to discuss Iran’s nuclear program with President Putin, who just returned from talks with Iranian leaders in Tehran.

The two leaders also were expected to discuss a reported arms deal that Russia is to sign with Syria, and Russia’s role in Israeli-Palestinian Arab peacemaking efforts.

Mr. Olmert’s visit, expected to last just a few hours, was announced only after Mr. Putin had returned from Iran, where he vowed Tuesday to support Iran’s pursuit of nuclear energy and warned “outside forces” — hinting at America — against using force against Tehran.

After greeting Mr. Olmert at the Kremlin, Mr. Putin said, “We know how concerned you are about the situation surrounding the Iranian (nuclear program). I am ready to share the results of my visit.”

In response, Mr. Olmert said he would “be glad to hear from you about the results of your trip to Iran and talk about other concerns.”

Journalists were escorted out of the room after the brief remarks.

Earlier, an Israeli government spokeswoman, Miri Eisin, said Mr. Olmert would make clear the Israeli position that an Iranian nuclear capability would threaten the world.

According to Israel’s Yediot Ahronot newspaper, Mr. Olmert was carrying “an unequivocal message to the Russian president: In a situation in which Iran has nuclear weapons and Syria has sophisticated weapons from Russia, Israel will have to weigh its actions against these threats.”

Israel considers Iran to be a threat to its existence, while Russia is a major provider of technology for Tehran’s nuclear program, which Washington and its Western allies suspect is directed at the development of nuclear weapons.

Mr. Putin’s meeting with President Ahmadinejad of Iran was likely seen by both Iran and Israel as a show of support for a president who has called for Israel’s demise.

President Bush said yesterday he wanted to get a readout directly from Mr. Putin about his visit to Iran, and to know whether Mr. Putin “continues to harbor the same concerns” as Mr. Bush about Iran’s nuclear program. He also issued a warning that a nuclear-armed Iran could trigger World War III.