Hillary Clinton sought to calm Israeli fears about a nuclear-armed Iran yesterday after she appeared to suggest last week that the Obama Administration was resigned to Tehran getting the bomb.

Iranian technicians work at the Isfahan Uranium Conversion Facilities in 2007. US Secretary of State Hillary Clinton has warned Iran that any pursuit of a nuclear weapons program is "futile," but acknowledged Washington is prepared to engage with whatever regime is in power in Tehran. (AFP/File/Behrouz Mehri) Israeli officials expressed concern after the US Secretary of State said in Thailand that a nuclear-armed Iran could be contained by a US "defence umbrella". Her words went beyond the Obama Administration's publicly stated Iran policy, which is focused on preventing Tehran from acquiring weapons of mass destruction.

Speaking on the NBC programme Meet the Press yesterday, Mrs Clinton said that Iran's pursuit of a nuclear weapon was "futile". "What we want to do is to send a message to whoever is making these decisions that, if you're pursuing nuclear weapons for the purpose of intimidating, of projecting your power, we are not going to let that happen," she said.

Mrs Clinton spoke as America's leading Middle East envoy and a succession of senior officials headed for Jerusalem in an attempt to achieve an Arab-Israeli peace settlement.

Despite indications that Israel's relationship with the US has soured in recent months - a direct result of President Obama's efforts to engage directly with the Iranian leadership - diplomats maintained that the wave of visiting officials showed that peace was high on the White House agenda.

The head of Iran's Revolutionary Guard responded aggressively to fresh speculation in the region over Israeli plans to attack its nuclear programme. "If the Zionist regime attacks Iran, we will surely strike its nuclear facilities with our missile capabilities," Mohammad Ali Jafari said. "Our missile capability puts all of the Zionist regime within Iran's reach to attack."

Binyamin Netanyahu, the Israeli Prime Minister, said that there were "naturally" differences of opinions between Israel and the US but that the sides were "trying to reach an understanding".

Officials will discuss issues ranging from Jewish settlements to Iran's nuclear ambitions, beginning today with the arrival of the US envoy to the Middle East, George Mitchell, and followed tomorrow by Robert Gates, the Defence Secretary.

James Jones, the National Security Adviser, and Dennis Ross, the special adviser to President Obama, will arrive on Wednesday and speak to Israeli security officials.

Israel is being pushed to make compromises towards a peace deal that would include closer ties with neighbouring Arab states. Aides close to Mr Netanyahu, though, said that he might not be prepared to make some of the concessions demanded by the Americans.

The key stumbling block remains Israel's settlements policy, in which building will continue on land that has been earmarked for a future Palestinian state. Israel has suggested that it would freeze some building work while allowing projects already under way to continue and to accommodate for "natural growth" of the settlements.

The US has argued that continued settlement building has been a key deterrent in talks with Arab states.

Speaking from Damascus, Mr Mitchell said that restarting talks between Israel and Syria was a "near-term" goal for Washington. "I told President Assad that President Obama is determined to facilitate a truly comprehensive Arab-Israeli peace," he said. "That peace means between Palestinians and Israelis, between Syria and Israel, and between Lebanon and Israel. This is what the Arab peace initiative calls for, and it is the ultimate aim of the effort we are undertaking."

Israeli officials described the talks as part of a "multi-pronged initiative" to neutralise the Iranian threat.

"There are a number of countries who are feeling the threat of Iran's growing influence. We have points of interest in common that we could use to strengthen as a framework for talks," a senior official at the Foreign Ministry said.

The threat of a nuclear Iran has long been at the top of Israel's foreign policy agenda. Aides to Mr Netanyahu confirmed that Israel was being pushed to make concessions towards a future Palestinian state while receiving international support to stop Iran's nuclear weapons programme.

"It is an issue of priorities, and Israel is being pressed to quickly define its interests," an aide said.

Political analysts say that Mr Netanyahu will not find it easy to convince his largely right-wing coalition to accept some of the compromises proposed by the Americans.

Jewish settler leaders and MPs from within Mr Netanyahu's coalition have promised to "go to war" with any person who seeks to uproot Israel's West Bank settlements.

To prove their point, settlers announced plans to construct 11 new outposts in the West Bank beginning today. In fliers distributed over the weekend settlers announced that they would construct 11 outposts to "put an end to the White Papers" - a reference to a decision made by the British Mandate in 1939 to limit Jewish immigration and building to 11 settlements in the Negev.

In a sermon, the Jewish spiritual leader Rabbi Ovadia Yosef criticised President Obama and other Western leaders for pressuring Israel to freeze construction in the West Bank and east Jerusalem.