US defence chief in Middle East
US defence chief Ashton Carter begins Middle East tour after Iran nuclearReuters

US Secretary of Defense Ashton Carter is set to begin a tour of the Middle East to strengthen Washington's ties with the countries in the region following the Iran nuclear deal.

Carter will land in Israel, which reserved the harshest criticism for the nuclear agreement, to hold security meetings. He will hold talks with Israeli Prime Minister Benjamin Netanyahu and Defence Minister Moshe Ya'alon.

This is Carter's first visit to Israel since he took over as the defence chief. Israel is expected to seek increased military aid from the US to balance the nuclear accord with Iran.

"The deal won't change radically what we do here at the Defense Department. We are committed to maintaining a strong presence, particularly in the Gulf," a senior Pentagon official told AFP.

"But frankly, they are the same conversation we would have if there was no deal that had been signed. We will be prepared and postured to support the security of our allies, particularly Israel."

Carter will arrive in Israel hours after US Secretary of State John Kerry spoke to Netanyahu over telephone following which the top American diplomat derided critics for "fantasy" of a "better deal" with Iran.

Carter's diplomatic charm offensive will also take him to Saudi Arabia, a Sunni-inclined kingdom and another strong critic of Iran, and Jordan.

He will visit the military base in Jordan which is not far away from the Syria border. He will also meet key coalition partners who are currently participating in the battle against Islamic State (Isis).