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

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

“Ayatollah Khamenei emphasised 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 defence forces.

“The Supreme Leader said … the air defence 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 fulfil 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.”

More than two million Muslims gathered at Mount Arafat on Monday for a vigil to atone for their sins and ask God’s forgiveness as the annual haj pilgrimage in Saudi Arabia reached its climax.

Pilgrims clad in white robes signifying a state of purity spent the night in an encampment around the hill where Islam holds that God tested Abraham’s faith by commanding him to sacrifice his son Ismail and Prophet Mohammad gave his last sermon.

Other worshippers praying in the nearby Mina area ascended in buses or on foot from before dawn as security forces directed traffic and helicopters and surveillance drones hovered overhead.

Some pilgrims carried umbrellas to protect themselves from the sun as temperatures surpassed 40 degrees Celsius (104 degrees Fahrenheit) after an evening of thunderstorms and high winds. Men and women from 165 countries gathered side by side, while soldiers handed out bottled water and some people snapped selfies.

Pakistani pilgrim Mohamed Forqan, 30, said it was a great day to be a Muslim. “Here in Arafat we feel that we are born today asking Allah to forgive our sins,” he said.

Hilal Issa, 70, from Algeria, said he was praying for God to pardon all Muslims and save the Arab world from its afflictions.

Saudi Arabia has said more than 2.3 million pilgrims, mostly from outside Saudi Arabia, have arrived for the five-day ritual, a religious duty once in a lifetime for every able-bodied Muslim who can afford the journey.

The pilgrims will spend the day on Mount Arafat. By sunset they will move to the rocky plain of Muzdalifa to gather pebbles to throw at stone columns symbolising the devil at another location called Jamarat on Tuesday, which marks the first day of Eid al-Adha, or the feast of sacrifice.

A new kiswa, the cloth embroidered with verses from the Koran, was placed over the Kaaba in Mecca’s Grand Mosque late on Sunday. Pilgrims will return to pray there at the end of haj.

CALLS FOR UNITY

In a haj message, Ayatollah Ali Khamenei, leader of Saudi-rival Iran, called for unity among Muslims as a defence against foreign enemies.

“Muslims should be vigilant about America’s malicious war-mongering policy aimed at Muslims killing Muslims,” he said in comments read by a representative on Iranian television.

The United States reimposed economic sanctions on Iran this month after pulling out of a 2015 international deal aimed at curbing its nuclear programme in return for easing sanctions.

Washington has said Tehran’s only chance of avoiding the sanctions would be to accept President Donald Trump’s offer to negotiate for a tougher nuclear deal, which Iranian officials have rejected.

In a midday sermon, senior Saudi cleric Sheikh Hussein bin Abdulaziz Al al-Sheikh also urged pilgrims to come together with their co-religionists but cautioned: “Haj is not a place for slogans and parties.”

Saudi Arabia stakes its reputation on its guardianship of Islam’s holiest sites – Mecca and Medina – and organising the pilgrimage.

The world’s largest annual gathering of Muslims has in the past seen stampedes, fires and riots, with authorities sometimes struggling to respond. A crush in 2015 killed nearly 800 pilgrims, according to Riyadh, although counts by countries of repatriated bodies showed over 2,000 may have died, more than 400 of them Iranians.

Officials say they have taken all necessary precautions this year, with tens of thousands of security forces and health workers on hand to maintain safety and provide first aid.

Pilgrimage is also the backbone of a plan to expand tourism under a drive to diversify the kingdom’s economy away from oil. The haj and year-round umrah generate billions of dollars in revenue from worshippers’ lodging, transport, fees and gifts.

Officials aim to increase the number of umrah and haj pilgrims to 15 million and 5 million respectively by 2020, and hope to double the umrah number again to 30 million by 2030.