Iranian Supreme Leader Ali Khamenei said on Sunday war was unlikely but called on Irans armed forces to boost their defense capacities. 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 US pullout from Tehrans nuclear agreement with world powers. "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," his website quoted Khamenei as telling commanders of Irans 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 Irans Air Defense Day. Saturdays news of the military development plans came a day after Iran dismissed a French call for negotiations on Tehrans future nuclear plans, its ballistic missile arsenal and its role in wars in Syria and Yemen. Iranian President Hassan Rouhani said last month the countrys 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 US pullout from the accord and the reimpositions of sanctions by Washington, the state news agency IRNA reported. "The imposition of (US) 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 US sanctions. "European countries have not been able yet to take necessary measures to secure Irans interests under the nuclear agreement," Kharrazi said. "(Burt) said Britains 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.