TEL AVIV // The US national security adviser yesterday became the latest American official to discuss Iran's nuclear ambitions with Israeli leaders amid reports that Tehran is ready to expand uranium enrichment and speculation of an Israeli attack on Iran.
As the administration of Barack Obama, the US president, grows increasingly concerned that Israel may opt to launch a strike, Tom Donilon met Benjamin Netanyahu, the prime minister, and Ehud Barak, the defence minister.
Martin Dempsey, the US military chief, visited last month and Mr Netanyahu travels to Washington next month to discuss Iran with US officials on the Iran issue.
The flurry of meetings on Israel came amid reports that Iran is poised to greatly expand uranium enrichment at a fortified underground bunker so that it can make nuclear warheads quickly.
That prospect may strengthen Israel's case for launching an attack on Tehran's nuclear sites.
The US and other western countries want to put off such a strike and wait for aggressive international sanctions on Iran to take hold and dissuade Tehran from advancing its plans.
Mr Dempsey said yesterday it was "not prudent at this point to decide to attack Iran". In London, William Hague, the British foreign secretary, warned that military action would not be "a wise thing".
Iran said yesterday it had stopped selling its crude oil to French and British companies, an escalation in its rhetoric that is unlikely to have any impact. The UK imports no Iranian oil and Total, the largest French oil company and once the main importer of Iranian oil to France, stopped buying from Tehran late last year.
In Israel, officials have suggested the country may still embark on military action despite pressure from allies.
Benny Gantz, the chief of the Israeli armed forces, indicated on Saturday that despite allies' pressure Israeli leaders may decide on a strike. "Israel is the central guarantor of its own security," he said.
Should Israel decide to strike, Gen Gantz will face the challenge of preparing the military for the attack as well as for any reprisal that some experts predict could spark a wider war in the Middle East.
On Saturday, during televised interviews marking his first anniversary on the job, he said: "During fighting I would not want to be on the other side - it will be much worse there."
Despite comments that reflect a possible readiness for an Iran attack, Gen Gantz has gained a reputation as being reluctant to carry out such a strike before all other avenues are explored.
"There are no doves in the Israeli security establishment vis-à-vis Iran - there is a consensus that a nuclear-armed Iran is unacceptable," said Amir Oren, a commentator for the Haaretz newspaper. "The dividing line is between those who think the time to act is now and those who believe we are not there yet. Gen Gantz is considered a leader of the less hawkish school of thought."
Mr Oren said Gen Gantz would prefer to "wait for proof" that Iran had crossed the threshold from uranium enrichment towards nuclear weapons proliferation - a line that western officials say has not yet been passed.
Gen Gantz, however, is less cautious on other security threats. Foremost, that includes rocket barrages from the Gaza Strip.
In December, the third anniversary of Israel's Gaza campaign in which about 1,400 Palestinians were killed, Gen Gantz said another such large-scale operation would have to be launched "sooner or later."
The 52-year-old son of European Holocaust survivors is no stranger to handling hostilities.
Gen Gantz has spent his entire career in the Israeli army since joining its ranks at 18, most recently serving as deputy army chief of staff. He also headed the military's West Bank division in 2000 during the outbreak of the second Palestinian intifada and was a top commander in the years preceding - and during - Israel's 34-day war with Hizbollah in 2006.
Several analysts have speculated that Gen Gantz may be taking a cautious stance on striking Iran, biding his time to better prepare the Israeli forces for such an attack.
The father of four had drawn some criticism that he did not do enough as chief of the northern command between 2002 and 2005 to prevent Hizbollah from deploying near the Israel-Lebanon border. Both the Israeli military and government had drawn much domestic criticism for their handling of the war in its aftermath.