A row between the US and Benjamin Netanyahu has deepened, with the Israeli leader accusing America and others of "giving up" on trying to stop Iran obtaining nuclear weapons.
The US secretary of state questioned Mr Netanyahu's judgement on the issue.
Republican leaders have invited Mr Netanyahu to address the US Congress next week, angering Democrats.
A White House spokesman warned against reducing US-Israeli ties to a party political issue.
Earlier, US National Security Adviser Susan Rice said Mr Netanyahu's visit was "destructive to the fabric of the relationship".
'May not be correct'
In response Mr Netanyahu said the US and others were "accepting that Iran will gradually, within a few years, develop capabilities to produce material for many nuclear weapons".
"I respect the White House and the president of the United States but on such a fateful matter, that can determine whether or not we survive, I must do everything to prevent such a great danger for Israel," he said in a speech in Israel.
Late on Wednesday US Secretary of State John Kerry rebuffed Mr Netanyahu, saying: "He may have a judgment that just may not be correct here."
He said it was premature to criticise the negotiations with Tehran. "The president has made clear - I can't state this more firmly - the policy is Iran will not get a nuclear weapon," Mr Kerry told senators.
He was speaking after returning from the latest round of nuclear talks involving Iran in Geneva.
Analysis - Barbara Plett Usher, BBC News, Washington
Administration officials have been hitting back at Mr Netanyahu's aggressive opposition to the nuclear deal they're negotiating with Iran - they're unhappy his speech to Congress will give him a platform to make his case as talks reach a critical juncture.
Susan Rice's comments highlight that strain and are the most direct reference by a senior official to the damage caused by the controversy over the visit. It was arranged by Republican congressional leaders without consulting the Democrats or the White House, just two weeks before Mr Netanyahu faces an election.
That has angered Democrats, some of whom feel they'll be forced to choose between President Obama and their desire not to upset Israel. More than a dozen have said they plan to skip the speech, opening an unprecedented breach in the usual show of bipartisan support for Israel.
Mr Netanyahu was invited by House Speaker John Boehner in what is seen as a rebuke to US President Barack Obama's Iran policy.
Mr Netanyahu is expected to discuss Iran, as well as Islamist militant groups, in his address.
The current tensions took root over a decade ago when Iran's nuclear programme first came to light.
In 2005, Iran was referred to the UN Security Council, leading to a series of sanctions and UN resolutions requiring Tehran to stop enriching uranium.
The US and other powers - the so-called P5+1 - are negotiating with Iran on its nuclear programme. They want to agree a deal by March this year, but Mr Netanyahu is opposed to any agreement which might allow Tehran to retain the future capacity to build a nuclear weapon.
'Breach of protocol'
The Israeli leader has turned down an invitation to meet Senate Democrats privately, saying this "could compound the misperception of partisanship" surrounding his trip.
Several Democratic members of Congress including Vice-President Joe Biden have said they will not attend the speech.
Republican leaders did not consult the Obama administration before inviting Mr Netanyahu, which the White House has called a breach of protocol.
White House spokesman Josh Earnest said on Wednesday: "The president has said the relationship between the US and Israel can't just be reduced to a relationship between the Republican party and the Likud party."
Mr Obama does not plan to meet Mr Netanyahu next week. The White House cited the "long-standing practice" of not meeting government leaders close to elections, which Israel will hold in mid-March.
Mr Netanyahu is fighting a tough election against the Labour Party's Yitzhak Herzog, who has focused on the prime minister's cooler relations with Mr Obama.