MOSCOW – A diplomatic crisis is brewing over Russia’s potential sale of advanced missiles to Syria, a sworn enemy of Israel accused of supporting Hezbollah and Palestinian Arab terrorists.

Israel’s Channel Two TV reported yesterday that Russia plans to sell arms to Syria, including shoulder-fired missiles, which could threaten Israeli aircraft. In a separate report, the Russian newspaper Kommersant said the sale would include Iskander-E ground-to-ground missiles, which would give Syria the capability to strike almost anywhere in Israel.

President Assad will discuss the deal during a four-day visit to Moscow starting January 24, Kommersant reported.

Israeli officials told the Associated Press yesterday that tensions are high and that negotiations aimed at stopping the sale are ongoing.

“We have enough problems on the ground with Syria and we don’t need more problems from the sky,” the Israeli vice premier, Shimon Peres, said.

Asked about the deal, Israel’s foreign minister, Silvan Shalom, said: “We have close contacts with the Russians. We had consultations over the past few days, and we hope to reach the necessary agreement.”

Washington has been made aware of the growing crisis and may eventually be asked to get directly involved, officials said.

The State Department’s spokesman, Richard Boucher, told reporters: “We have reports of the sale. The U.S. policy on this is very clear: We’re against the sale of weaponry to Syria, against the sale of lethal military equipment to Syria, which is a state sponsor of terrorism, and we think those kinds of sales are not appropriate. The Russians know about this policy.”

In Moscow, officials refused to confirm or deny the sale, but did try to downplay tensions.

“We do not note any signs of deterioration in our relations with Israel,” the Foreign Ministry’s spokesman, Alexander Yakovenko, said in a statement. “On the contrary, by our assessment, Russian-Israeli ties are developing steadily and in a constructive spirit.”

While defending Russia’s right to trade arms with countries like Syria, which is not under an international embargo, Mr. Yakovenko also noted that Russia “in our export policy pays special attention to preventing sensitive types of weaponry from falling into the hands of international terrorists, and this is known to the Israeli leadership.”

Defense experts in Russia were skeptical about the deal going through.

“Our producers want to sell and Syria wants to buy, but there are a lot of things in the way,” an independent security analyst, Pavel Felgenhauer, said. “First of all, the Syrians don’t have enough money for a major arms purchase. … And the Israelis are very concerned about this for obvious reasons, and they, along with the Americans, will put a lot of political pressure on Russia.”

Mr. Felgenhauer noted that reports of major arms sales from Russia to Syria “crop up all the time, but they never materialize.”

Russia last sold weapons to Syria two years ago, when Damascus purchased more than $130 million worth of Kornet and Metis anti-tank missiles. Washington imposed sanctions on the company after the sale and Mr. Felgenhauer said the sale of more powerful weapons could lead to wide-ranging sanctions against Russia.

“Russia would certainly be reluctant to get into a position where it could be sanctioned,” he said.

Israel’s Channel Two reported that the purchase involved Igla SA-18s, one of the most sophisticated shoulder held anti-aircraft missiles available. Israeli officials fear the missiles could end up in the hands of Lebanon’s Hezbollah terrorists or Palestinian Arab terrorists. Syria openly backs Hezbollah and has been accused of supporting terrorist groups behind the four-year-old uprising in the Gaza Strip and the West Bank.

Of perhaps even more concern to Israel would be the acquisition by Syria of Iskander-E missile complexes. The Iskander, mounted on truck launchers and also known as the SS-26, is an updated version of the Soviet-era Scud missile used by Iraq against Israel during the Gulf War. The missile, which reportedly can overcome existing air defense systems, can destroy targets up to 175 miles away. If Iskanders were deployed, for example, near the demarcation line in the Golan Heights area, almost all of Israel’s territory, including the Dimona nuclear center in the Negev desert, would be at risk. Each missile has two 1,055-pound warheads and can hit targets with an accuracy of 20 yards.

Kommersant reported that Syria sought to buy 18 Iskander-E complexes from Moscow two years ago, but the equipment had not yet been tested. Successful testing was completed in August and Syria confirmed its interest in buying the systems last week, the paper said.

Israeli defense officials said the report about the sale of Iskander missiles was untrue, AP reported.

Earlier this month, the Israeli press reported that Prime Minister Sharon convened a special Cabinet meeting on January 4 on Russian-Israeli relations. The meeting was reportedly devoted to discussing certain unfriendly steps taken by Russia toward Israel, but the press was not specific about the causes of the tension. Mr. Sharon reportedly informed the Americans of the crisis on Tuesday. According to Israeli public radio, relations with Russia are now being managed personally by Mr. Sharon, Mr. Shalom, and the defense minister, Shaul Mofaz.

A cooling of relations between Russia and Israel would reverse 15 years of dramatic improvements in dealings between the two nations. The Soviet Union nurtured close ties with Israel’s enemies in the Arab world throughout the Cold War, but in recent years Russia has sought to better its relations with the Jewish state. Russia is a member of the so-called Quartet of Middle East mediators, which has supported the “road map” deal, the only internationally backed peace initiative for the region. The other members are America, the European Union, and the United Nations.