President Barack Obama called Benjamin Netanyahu Tuesday after he provoked a sudden crisis in relations by warning Washington had no moral right to stop Israel attacking Iran's nuclear program.

In an unusual move, Obama called the Prime Minister in the early hours Israel time, after a day of fast-rising tensions, exacerbated when Israeli officials said Obama had snubbed Netanyahu's request for talks on US soil.

The spat erupted less than two months before the US presidential election, as Republican nominee and Netanyahu friend Mitt Romney seeks to dent Obama's foreign policy prestige by accusing him of deserting Israel and appeasing Iran.

A US statement said the call lasted an hour and insisted there was no rift over how to handle Iran, but left the impression Obama was irked at Netanyahu's rhetoric on a key foreign policy crisis weighing on his re-election hopes.

"President Obama and Prime Minister Netanyahu reaffirmed that they are united in their determination to prevent Iran from obtaining a nuclear weapon, and agreed to continue their close consultations going forward," it said.

The statement also said that contrary to reports in the Israeli press "there was never a request for Prime Minister Netanyahu to meet with President Obama in Washington, nor was a request for a meeting ever denied."

An Israeli official told AFP earlier that Netanyahu had asked for talks later this month at the UN General Assembly, but that the White House said the president's "very tight schedule" as he runs for reelection would not allow it.

Then, as bad feeling bubbled between the allies, the Israeli Haaretz newspaper quoted an unnamed Israeli official as saying Netanyahu had even offered to come to Washington for talks.

The Israeli leader angered Obama aides, who have seen Republicans accuse the president of throwing Israel "under the bus," when he publicly criticized Washington's refusal to set "red lines" for action on Iran's nuclear program.

"The world tells Israel: Wait, there's still time. And I say: wait for what? Wait until when?" Netanyahu said in English on Tuesday, in comments clearly aimed directly at the White House.

"Those in the international community who refuse to put red lines before Iran don't have a moral right to place a red light before Israel," he said.

Publicly, the White House said the lack of talks in New York was purely a matter of scheduling.

"They're simply not in the city at the same time," National Security Council spokesman Tommy Vietor said.

Obama arrives on Monday, September 24 and leaves the next day while Netanyahu is not due in New York until later in the week, Vietor said, adding that the Israeli leader would meet Secretary of State Hillary Clinton.

The dispute came amid fervent speculation that Netanyahu could order a unilateral strike on the Islamic Republic's nuclear program -- an action Washington believes would be premature.

The White House says there is still time for diplomacy and sanctions to change Iranian behavior, though it warns Obama is ultimately prepared to use force to stop the Islamic Republic getting a nuclear weapon.

Washington has been unwilling to publicly state "red lines" for action, fearing that Iran will trigger an immediate crisis by going right up to them in a game of nuclear brinkmanship.

With an eye on the votes of American Jews, Romney traveled to Israel in July, and an aide suggested that if he were president, the US definition of the immediacy of the Iranian threat would be closer to Netanyahu's.

Romney is expected to weigh in on the latest US-Israel spat on Wednesday and may also touch on a building crisis which has seen armed mobs angry at a film offensive to Islam attacking a US consulate in Benghazi, Libya, killing an American, and storming Washington's embassy in Cairo.

The White House argues that no president has done more than Obama to protect Israel.

Netanyahu views Iran's nuclear program as an existential threat, and portrays Tehran as approaching a critical point in its capacity to enrich uranium at levels pure enough for nuclear weapons.

Obama has repeatedly stressed that he will not allow Iran to get to the point of actually weaponizing a device, seeing that threat as less immediate.

Furthermore, Washington believes it has sufficient intelligence capability to determine if Iran decides to cross that threshold and has enough time to act.

Iran denies it is seeking nuclear weapons.

Obama and Netanyahu have a tense history. When they last met in March, Netanyahu warned that Israel must remain the "master of its fate" in a firm defense of his right to mount a unilateral strike on Iran.

The year before, Netanyahu sparked fury here when he delivered a stinging public lecture to Obama on the history of the Jewish people in the Oval Office.