Pentagon chief tries to calm Mideast jitters over Iran deal

US Defence Secretary Ashton Carter sought to reassure anxious Middle East allies Tuesday over the Iran nuclear deal during a regional tour that includes stops in Israel, Jordan and Saudi Arabia, AFP reports.

Carter met Israeli Prime Minister Benjamin Netanyahu, a fierce critic of the landmark Iran accord, before flying on to Jordan, a key partner in the US-led war on the Islamic State (IS) group.

Addressing military personnel from six nations in the anti-jihadist coalition at a Jordanian airbase, he said the United States and Israel had a "common commitment to countering Iranian malign influence in the region".

Netanyahu "made it quite clear that he disagreed with us with respect to the nuclear deal and Iran. But friends can disagree," Carter said.

"We will continue to work with Israel and other partners in this region to counter the danger from Iran, even as we do the same with respect to ISIL," he said, using another acronym for IS.

Meeting Italian Prime Minister Matteo Renzi in Jerusalem Tuesday, Netanyahu underlined Israeli opposition to the Iran deal.

"It will put Iran at the threshold of an entire nuclear arsenal within a decade," he said.

Carter met American forces stationed in Jordan, which shares borders with both Syria and Iraq, and colleagues of Jordanian pilot Lieutenant Maaz al-Kassasbeh, who was captured by IS after his plane crashed in Syria and later burned alive by the group in a gruesome video.

His murder caused global revulsion and vows of international efforts to combat the Sunni extremist group.

    'Barbarians are always defeated' 

"The enemy has to be defeated," Carter told US mechanics beside an American F-16 at the base.

"It will be, because the barbarians are always defeated by civilisation, a few by the many."

He later had a private meeting with pilots taking part in anti-IS coalition sorties.

Carter is due in Saudi Arabia on Wednesday for a visit expected to be dominated by concerns about the Iran nuclear deal.

Sunni-ruled Gulf states are wary of the US overtures to arch-foe Iran, believing the deal will only embolden Tehran's Shiite leaders.

US Secretary of State John Kerry told Saudi-owned Al-Arabiya television in an interview broadcast Tuesday he would tell Gulf foreign ministers in Qatar next month "all of the ways in which this agreement, in fact, makes the Gulf states and the region safer".

Israel also fears the agreement is not enough to keep the Islamic republic from obtaining nuclear weapons that could be used against it.

Netanyahu has said military force remains on the table to block Iran's path to a nuclear weapon, although experts say unilateral strikes by Israel appear highly unlikely for now.

Iran is accused of supporting militants in the region, including Israeli enemies Hezbollah and Hamas, and Israel argues that the expected lifting of sanctions under the nuclear accord will allow it to boost help for such groups.

Carter sought Monday to address Israeli worries that Washington was shifting its focus in the region, saying Israel remained "the bedrock of American strategy in the Middle East".

    'Give and take' 

Under the July 14 agreement, Iran agreed to dismantle or mothball much of its nuclear industry in return for an easing and eventual lifting of sanctions.

Tehran insists its nuclear programme is peaceful.

World powers called it an historic opportunity to set relations with Iran on a new path, but the deal has faced opposition from hardliners both in Tehran and Washington.

On Tuesday, Iranian Foreign Minister Mohammad Javad Zarif defended the agreement in a speech to parliament in Tehran, saying "we should not forget that any deal is a give and take".

"Each side gives up part of its demands to realise the more important part until what has been given and received is balanced," he said.

There have been fears by some that such moves could contribute to a new conventional arms race in the already volatile Middle East.

"That has not happened here for at least two decades," said Eytan Gilboa, a political science professor at Bar Ilan University near Tel Aviv.

Netanyahu has urged US lawmakers to reject the deal. He angered President Barack Obama by appearing before Congress in March to denounce the emerging accord.

Gilboa said Israel is likely to hold off on discussions of "compensation" in the form of increased military aid until later to avoid signalling to Congress that it accepts the agreement.

"Israel wants to show that it is naive to assume that with this agreement you can change the government of Iran," he said.