DUBAI (Reuters) - Iranian Supreme Leader Ayatollah Ali Khamenei said on Sunday war was unlikely but called on Iran’s armed forces to boost their defense capacities, according to his official website, as the country faces increased tension with the United States.

FILE PHOTO - Iran's Supreme Leader Ayatollah Ali Khamenei speaks at the Hussayniyeh of Imam Khomeini in Tehran, Iran, August 13, 2018. Official Khamenei website/Handout via REUTERS

On Saturday, Iran announced plans to boost its ballistic and cruise missile capacity and acquire modern fighter planes and submarines to boost its defenses following the U.S. pullout from Tehran’s nuclear agreement with world powers.

“Ayatollah Khamenei emphasized that based on political calculations there is no likelihood of a military war but added that the armed forces must be vigilant ... and raise their personnel and equipment capacities,” the website quoted Khamenei

as telling commanders of Iran’s air defense forces.

“The Supreme Leader said ...the air defense units were a very sensitive part of the armed forces and on the front line of confronting the enemy, and emphasized the need to increase their readiness and capabilities,” the website said in its report on the gathering, which was held to mark Iran’s Air Defence Day.

Saturday’s news of the military development plans came a day after Iran dismissed a French call for negotiations on Tehran’s future nuclear plans, its ballistic missile arsenal and its role in wars in Syria and Yemen.

Iranian President Hassan Rouhani said last month the Islamic Republic’s military prowess was what deterred Washington from attacking it.

Separately, a senior Iranian diplomat met visiting UK Junior Foreign Minister Alistair Burt and urged swift European action on a planned package of economic measures to offset the U.S. pullout from the accord and the reimpositions of sanctions by Washington, the state news agency IRNA reported.

“The imposition of (U.S.) sanctions and pressures and the lack of rapid action by Europe to fulfill their commitments will have serious consequences,” Kamal Kharrazi, a former foreign minister who heads a top foreign policy council, told Burt, IRNA reported.

Iranian officials have said they would decide whether to quit the 2015 nuclear deal with world powers after studying the European package of economic measures that could help offset U.S. sanctions.

“European countries have not been able yet to take necessary measures to secure Iran’s interests under the nuclear agreement,” Kharrazi said.

“(Burt) said Britain’s position is different from that of the United States and we are looking for a European mechanism to make the nuclear accord successful,” IRNA reported.

In a meeting with senior parliamentarian Heshmatollah Falahatpisheh, Burt referred to the case of a British-Iranian dual national detained in Iran, IRNA reported.

“I thank Iran for its humanitarian act to grant Nazanin Zaghari furlough and her meeting with her family, and we hope that this approach will continue until the release and the pardon of such people,” Burt said, according to IRNA.

Britain is seeking the release of Nazanin Zaghari-Ratcliffe, a project manager with the Thomson Reuters Foundation. She was arrested in April 2016 at Tehran airport as she was heading back to Britain with her daughter, now aged four, after a family visit. She was released for three days last month.

Burt, on the first visit by a British minister since U.S. President Donald Trump withdrew from the nuclear deal, earlier met Iranian Deputy Foreign Minister Abbas Araghchi.

Iranian Foreign Minister Mohammad Javad Zarif said on Saturday the talks with Burt had involved “access to banking resources and the sale of oil”.

Iran has been seeking commitment from European signatories of the nuclear deal that it will be able to access the Western banking system and continue to sell oil despite U.S. sanctions.

In a statement before his visit, Burt said: “As long as Iran meets its commitments under the deal, we remain committed to it as we believe it is the best way to ensure a safe, secure future for the region.”