Rishi Sunak has sought to convince European leaders to support his plans to detain and remove people to Rwanda – using a summit address to link the “lessons” of the Ukraine war to what he said was a need to confront threats such as illegal migration. Downing Street earlier hailed an agreement reached between Sunak and the European Commission president, Ursula von der Leyen, to establish a new working arrangement to “strengthen cooperation” between the EU and the UK on migration. The arrangement would see British agencies working together with Frontex, the EU border force, on “critical operational and strategic challenges including the situation in the Channel”, a spokesman for Sunak said. The prime minister used his spot at the opening of the Council of Europe to push for cooperation to tackle illegal migration as he seeks to reassert his authority over the restless right wing of his party. Sunak said the dynamism of the European response to Russia had to be brought to bear on other issues, telling the Reykjavik summit: “We must also learn the lessons of this war by being prepared to confront threats to our societies before they become too big to deal with. “That includes acting on cybersecurity and AI and it means tackling illegal migration.” The moral case for action was clear, said Sunak, who went on to inject a Conservative electoral slogan into his address, telling the summit that more cooperation was needed across borders “to end illegal migration and stop the boats”. He had used discussions with other leaders, as well as a rare meeting with the president of the European court of human rights (ECHR), to seek backing for UK attempts to overcome rules that blocked the first scheduled deportation flight to Rwanda last summer. But others, including the Icelandic government – which is hosting the summit – played down the prospect of Sunak getting the agreement he wants to overcome the obstacles presented by the Stasbourg court. Iceland’s foreign affairs minister said the summit would not be used to reform an order that prevented the first deportation flight to Rwanda from taking off. “The leaders are reconfirming their commitment to the common human rights protection system and, in particular, the court is a cornerstone of our protection system,” Thórdís Gylfadóttir told BBC Radio 4’s World at One programme. “But the next two days, the time we have we are not using to reform certain articles in the court.” Tiny Kox, a Dutch politician who is the president of the Council of Europe’s parliamentary assembly, also told the Guardian the UK could end up like Russia if it just ignores court rulings, as the British government wants to give itself the ability to do. “We are not a cafeteria, where you can ask for the verdict of the court that suits you,” he said. Sunak also held talks with the president of the ECHR, Síofra O’Leary, over a review of how rule 39 works – the order that blocked the inaugural flight to Kigali last year. People trafficking came up in his bilateral meeting with Dutch leader Mark Rutte, with whom he agreed to “tackle the scourge” by working together “both bilaterally and through forums such as the European Political Community”, according to No 10. Looming over the talks is the memory of Sunak caving in last month to demands from hard-right MPs to allow the UK to ignore rulings from the European court of human rights on small boat crossings. Backbench rebels had been pushing the PM to harden the illegal migration bill so ministers could ignore interim rulings. One of the Strasbourg court’s rule 39 injunctions blocked the government’s first attempt to deport asylum seekers to Rwanda last year. The Council of Europe summit officially opened later on Tuesday evening, following a rendition of Ode to Joy by an Icelandic brass band, where the country’s prime minister, Katrín Jakobsdóttir, said in her address: “The very concept of universal human rights continues to be contested.”