US Ambassador Dan Shapiro on Monday sought to quell Israeli fears over an emerging deal with Iran, vowing that Washington would never let Tehran acquire a nuclear weapon.
"On this crucial issue the US and Israel share an identical agenda," Shapiro told delegates attending the General Assembly of the Jewish Federations of North America in Jerusalem.
US President Barack "Obama has made it crystal clear that he will not permit Iran to acquire a nuclear weapon period, and is prepared to use all elements of our national power to ensure that we are successful," he said.
His remarks were made as the US and Israel were locked in an escalating war of words over negotiations between world powers and Iran in a bid to halt its nuclear programme, which is widely believed to be a front for developing a military capability.
Diplomats have said they are closing in on an interim agreement that would freeze or curb some of Iran's nuclear activities for as long as six months in exchange for an easing of the tight sanctions on the Islamic republic, after failing to secure a deal at weekend crunch talks in Geneva.
In the past few days, Israel's Prime Minister Benjamin Netanyahu has furiously denounced the emerging agreement as "dangerous", reaching out to world leaders and to the American public to get his point across.
"Iran gives practically nothing and it gets a hell of a lot. That's not a good deal," Netanyahu told CBS on Sunday.
"It's a bad and dangerous deal that deals with the thing that affects our survival," he told a conference of North American Jewish groups in Jerusalem. "And when it comes to the question of Jewish survival and the survival of the Jewish state, I will not be silenced."
On Monday he made the same point at a meeting with Belgian Foreign Minister Didier Reynders.
"The common goal for ourselves, the United States, Europe, China and Russia is to stop Iran developing a military nuclear capability," a statement from his office quoted him as saying.
"I think this is the time to improve the agreement. Iran is in economic distress and it is possible to get a better deal," he said. "Before easing sanctions we need to get a good deal, not a bad deal."
US Secretary of State John Kerry, who took part in the Geneva talks, challenged Netanyahu's stand, saying Washington has the interests of ally Israel at heart and that he shares Netanyahu's "deep concerns".
"But I believe the prime minister needs to recognise that no agreement has been reached about the endgame here that's the subject of the negotiations," he said.
A delegation of US officials headed by chief negotiator Wendy Sherman visited Israel on Sunday to brief officials on the Geneva talks.
Maariv newspaper reported that a senior US official told Israeli reporters that the proposed sanctions relief would be "modest" could be "revoked".
The official said that intensifying sanctions would "cause the Iranians to leave the negotiating table and accelerate their nuclear program," according to Maariv.
Israel's Economy Minister Naftali Bennett is to travel to the United States on Tuesday, with part of his trip focusing on meetings with senators and members of the US Congress over the issue.
Israel, the region's sole if undeclared nuclear power, views a nuclear Iran as an existential threat and has said it will not be "bound" by any world deal with Tehran, refusing to rule out the threat of military action to halt it.