WASHINGTON — A senior Israeli delegation, here for strategic talks with top American government officials, is calling for an expiration date on the diplomatic approach to Iran of the end of the year.

Speaking to the Israeli press on Wednesday evening after meeting Secretary of State Rice, Israel’s deputy prime minister, Shaul Mofaz, said, “Sanctions must be strong enough to bring about change in the Iranians by the end of 2007.” According to a source familiar with discussions yesterday with the undersecretary of state, Nicholas Burns, Mr. Mofaz said, “Technical developments for the Iranian nuclear program will not follow a linear progression,” a clear warning that America’s official estimate that Iran will not attain an atomic bomb for at least five years could be dangerously optimistic.

The delegation headed by Mr. Mofaz also pressed in side talks for America to halt a proposed sale to Saudi Arabia of precision Joint Direct Attack Munitions. Already the proposed sale, which was announced in April by Secretary of Defense Gates, has caught the attention of a handful of lawmakers in the House, who on May 24 threatened to block any such sale once Congress was formally notified.

The combination of Israeli jitters on Iran’s continued effort to pack its Natanz facility with more centrifuge reactors with its jitters about providing precision munitions to the Saudis presents America with a dilemma. Since last fall, Ms. Rice has tried to forge a new alliance among Israel, Turkey, and Sunni monarchies in the Gulf to oppose what she sees as rising Iranian influence throughout the Middle East.

The prospect, however, of all these parties cooperating diplomatically was tested in March, when the Saudis brokered a unity government deal between the Palestinian Arab president, Mahmoud Abbas, and the Iranian-backed Hamas Party in the Palestinian territories, which controls the legislature and Palestinian Authority.

Channel 2 News in Israel reported that Mr. Mofaz said Israel would take military action if Iran did not cease its uranium enrichment by year’s end. However, a source familiar with yesterday’s discussions disputed the Channel 2 report. Mr. Mofaz only alluded to such action in the meeting, the source said, saying, “All options are on the table” if the diplomacy with Iran does not work.

“The Israelis are talking about taking it to the next level with a targeted and focused security coalition,” he said. “The other measures include working with Europeans and getting more action on the European side with specific sanctions. There has been some of this, but there has not been enough.”

The issue of Iranian nuclear enrichment was also broached yesterday in icy talks between President Bush and the Russian president, Vladimir Putin. The Russians have supported the two U.N. Security Council resolutions sanctioning Iranian banks and entities, but also have helped rebuild an Iranian nuclear facility in Bushehr.

The source familiar with the American-Israeli talks also said the Israelis raised the prospect of focusing sanctions on Iran’s energy sector, noting that the Iranians import more than half of their refined gasoline despite having the world’s third largest known reserves of oil and natural gas.

Publicly at least, Prime Minister Olmert has not said he would unilaterally bomb Iran. Last year he appointed one of Israel’s most hawkish politicians, Avigdor Lieberman, as a deputy prime minister and announced that Mr. Lieberman would oversee Iran policy. Other Israeli politicians such as a former premier, Benjamin Netanyahu, have openly called for Israel to take out the known Iranian nuclear facilities.
Within the American intelligence community, there is some debate about Israel’s capabilities in this regard.

Some argue that the Israelis still lack the midair refueling capacity they would need to conduct a bombing mission over Iran as a unilateral move.

Other analysts, however, point out that Israel’s fleet of American made F-15s has such refueling capacity, not to mention the capability of Israeli nuclear submarines. On background, Israeli former military officials have told The New York Sun that the option of a unilateral strike is there for Israel should Israel choose to take it.

In addition to discussing Iran, Mr. Mofaz shared new intelligence he said proved that missiles being shipped by land and air through Syria to Hezbollah positions in Lebanon could strike even at Tel Aviv and points south. One transshipment point for Syria, Mr. Mofaz said, was Turkey — an American ally and ally of Israel.

In last summer’s war between Israel and Hezbollah in Lebanon, the terror group’s leader, Hassan Nasrallah, threatened to send rockets to Tel Aviv but never fulfilled his promise.