WASHINGTON (AFP) - US President Barack Obama told a sceptical Benjamin Netanyahu on Tuesday that the freshly sealed Iran nuclear deal was in Israel's national interest and dispatched his secretary of defence to the Jewish state for talks.

The White House said Obama called the Israeli Prime Minister, who has described the accord as a "historic mistake," announcing Ash Carter would travel to Israel next week.

"The President told the Prime Minister that today's agreement on the nuclear issue will not diminish our concerns regarding Iran's support for terrorism and threats towards Israel," the White House said.

Obama expressed his "stalwart commitment to Israel's security" and said the Iran accord removed "the spectre of a nuclear-armed Iran, an outcome in the national security interest of the United States and Israel".

Netanyahu and Obama have clashed frequently and publicly over policy towards Iran.

In March, the Israeli leader even appeared in the Republican-controlled US Congress to trash a deal.

That brought opprobrium from the White House that included Obama refusing to host Netanyahu for a meeting.

Obama, for his part, donned a yarmulke at a conservative synagogue and pitched the deal directly to US Jews.

In a separate statement, Carter said the Pentagon remained "prepared and postured to bolster the security of our friends and allies in the region, including Israel".

That, Carter said, included moves to "check Iranian malign influence" and utilising "the military option if necessary."