Iran's foreign minister on Sunday called on Gulf Arab neighbours to cooperate against the common threat of "terrorism, extremism and sectarianism", but insisted that Tehran's regional policy will not change.

"Our message to the countries of the region is that we should cooperate to face the common threat," Mohammad Javad Zarif told reporters after meeting Kuwaiti officials on his first foreign trip since the nuclear deal with world powers.

"Iran has always supported the people of this region in confronting the common threat which is terrorism, extremism and sectarianism," he said.

However, Zarif also insisted that in order to spur cooperation in the region, it was up to other states to change their policies, not the Islamic republic.

"What is needed is not a change in Iranian policy but a change in the policy of some countries that want conflict and war in this region," Zarif said in a direct reference to Iran's main regional rival Saudi Arabia, but without naming it.

Since the end of March, Riyadh has led an air campaign against Iran-backed Shiite Huthi rebels in Yemen.

Zarif also denied as "baseless" claims by the Gulf state of Bahrain that it had detained two men for trying to smuggle weapons from Iran.

"I openly say the (Bahraini) claims are totally wrong," he said.

"The timing of the announcement is an attempt to prevent any progress in cooperation between Iran and other Gulf states," Zarif said.

Bahrain's interior ministry said late Saturday the two were arrested aboard a boat with machineguns, ammunition and C4 explosives, adding that the arms originated in Iran.

Zarif's tour will also take him to Qatar and Iraq, but he is not visiting Saudi Arabia or the United Arab Emirates, two key coalition members in the war against the Yemeni rebels.

The Iranian minister also strongly attacked the war in Yemen and called for an immediate ceasefire and dialogue.

The nuclear accord between Iran and Western powers, struck on July 14, imposes certain controls on Iran's nuclear programme in exchange for a lifting of crippling economic sanctions.

Gulf countries led by Saudi Arabia have been quick to voice concern about the agreement, which will see a progressive easing of international sanctions on Iran in place since 2006.

They fear that the deal could bolster their Shiite-dominated adversary, which stands accused of interfering in countries such as Iraq, Syria and Yemen.

Asked if Iran will change its policy in Syria and Iraq following the deal, Zarif said Iran has been at the forefront in fighting against the Islamic State group and Al-Qaeda, and its timely interference prevented the fall of Baghdad and Arbil to IS.

Zarif will return to Tehran next week where he will host EU foreign affairs chief Federica Mogherini before meeting his French counterpart Laurent Fabius.