President Barack Obama called Israeli Prime Minister Benjamin Netanyahu on Sunday to discuss an international nuclear deal with Iran that has threatened to raise tensions between the close allies, the White House said.

Just hours after the six world powers clinched the historic agreement with the Islamic republic, Netanyahu lashed out at what he called a "historic mistake" that left open Iran's ability to develop a nuclear arsenal.

But the five permanent members of the United Nations Security Council plus Germany -- known as the P5+1 -- involved in the talks hailed it as a key first step that for now warded off the prospect of military escalation.

"The two leaders reaffirmed their shared goal of preventing Iran from obtaining a nuclear weapon," deputy White House spokesman Josh Earnest told reporters aboard Air Force One As Obama headed to the US West Coast.

"Consistent with our commitment to consult closely with our Israeli friends, the president told the prime minister that he wants the United States and Israel to begin consultations immediately regarding our efforts to negotiate a comprehensive solution."

Obama stressed that the P5+1 will seek to obtain a "lasting, peaceful and comprehensive solution that would resolve the international community's concerns regarding Iran’s nuclear program," according to Earnest.

Israel and much of the West worry that Iran's nuclear program serves as a guise for a weapons drive, while Tehran denies the claim and insists it is only for civilian purposes.

Tehran has a long history of belligerent statements towards the Jewish state, notably under former president Mahmoud Ahmadinejad, and Israel has repeatedly warned that a nuclear Iran would pose an existential threat, refusing to rule out a preventative military strike on Iran's atomic infrastructure.

Some pro-Israel lawmakers in the US Congress have warned they plan to seek an additional round of sanctions when they return from their holiday recess next month.

Earnest expressed concern over the possibility of further US sanctions but stopped short of saying Obama would veto such a bill from Congress.

"The concern is that, rather than capitalizing on the diplomatic window that has opened up, doubling down on sanctions at this point would actually undermine the international coalition that we built," he said.

Earnest said Obama and Netanyahu agreed to keep in "close contact" over the deal.

"The president underscored that the United States will remain firm in our commitment to Israel, which has good reason to be skeptical about Iran’s intentions," he added.

Secretary of State John Kerry has also defended the accord, saying the agreement would blunt the threat and ultimately make the Jewish state more secure.

"You can't always start where you want to wind up," he said.

Iran agreed to curb its nuclear program for the next six months in exchange for limited sanctions relief, in a preliminary accord meant to lay the foundations for a comprehensive agreement later this year.

The deal was reached in marathon talks in Geneva that ended Sunday before dawn after protracted negotiations between Iran and the P5+1.

Source: AFP