US Defence Secretary Ashton Carter
US Defence Secretary Ashton Carter addresses reporters on a military aircraft en route to IsraelGetty Images

The use of military force is still an option to prevent Iran obtaining a nuclear bomb, US Defence Secretary Ashton Carter stressed on 19 July, ahead of a visit to Israel.

"One of the reasons why this deal is a good one is that it does nothing to prevent the military option," Carter told reporters en route to Israel, the first of several stops Carter will be making on a tour of the Middle East to ease concerns among allies over the landmark nuclear deal.

"We are preserving and continually improving" such a military option should Iran violate the terms of the agreement, Carter said, reports AFP, ahead of visits to Israel, Saudi Arabia and Jordan.

Israel has voiced strong criticism of the nuclear deal, signed between Iran and six world powers which would see economic sanctions lifted in exchange for increased international inspection of nuclear sites.

Carter will meet his Israeli counterpart, Moshe Yaalon, on Monday (20 July), and Israeli Prime Minister, Benjamin Netanyahu, for talks on Tuesday. Carter said that he will not seek to persuade Israel to drop its opposition to the nuclear deal, but will emphasise that under the terms of the agreement, the use of force remains an option.

He will reassure allies wary of the Iran deal that the US intends to maintain a strong military presence in the region to back its allies in face of a range of security threats.

Because of Iran's "potential for aggression and malign activities" as well as the fight against jihadist groups such as Islamic State (Isis), "we are always looking for ways to strengthen our posture there", Carter said.

He said that the US was working on a range of counterterrorism and defence measures with Israel, and the US hoped to increase cooperation with other regional allies in areas including counterterrorism, special operation forces, and maritime security.

In Saudi Arabia, Carter will meet King Salman, while in Jordan he will meet colleagues of pilot Moaz al-Kasasbeh, who was burnt alive after being captured by IS militants, as well as top military and government officials.