Hassan Rowhani open to return of diplomatic ties between Iran and Britain But he stressed that resolving the impasse over Iran's nuclear programme was key to improvements and cautioned against "lazy labelling" of Mr Rowhani as a moderate. "It is important for us to have an open mind but to judge Iran on its actions," he said. Mr Straw held talks with Mr Rowhani when he was Iran's nuclear negotiator and used a Daily Telegraph article on Monday to urge the government to reopen the British embassy in Tehran. Britain suspended diplomatic relations with Iran in November 2011 after hard-line demonstrators stormed the embassy complex in Tehran, smashing windows and damaging property. Senior Iranian officials, including Ayatollah Ali Khamenei, the supreme leader, have since expressed regret over the incident. However the scars left by the incident remain raw and Mr Hague said there would have to be guarantees that there would be no repeat of an invasion that was "state-sponsored in some way." Uncertainty over Mr Rowhani's scope to change Iran's outlook while Iran is ultimately under the authority of Ayatollah Khamenei will be the most important factor in Western policymakers' thinking. "There is a very big clue in the title of the supreme leader," said Mr Hague. Mr Rowhani's surprise victory against a field of hard-line conservatives has triggered cautious optimism of a gradual rapprochement between the West and Iran, which has been diplomatically isolated amid suspicions that its nuclear programme is a front for building a bomb. In a news conference in Tehran that saw him interrupted by applause at least six times, Mr Rowhani, who has been embraced by Iran's embattled reformist movement, said he would lead a government of "prudence and hope." He described the possibility of direct talks with the US - with whom Iran has had no relations since the 1979-81 Tehran embassy siege - as "complicated and difficult," adding: "This has been a very painful wound and we need to think of some way of healing this injury. We don't want to see more tensions. Wisdom tells us that both countries need to think more about the future and sit down to find a solution to past issues and rectify this. Asked if he would suspend Iran's uranium enrichment programme - as happened when he was nuclear negotiator - Mr Rowhani said "that time period was over." Iran would insist on its "nuclear rights." The conference ended suddenly however when a man jumped up and shouted a slogan in favour of Mirhossein Mousavi, the reformist leader held under house arrest since 2011. Television cut to scenes of people voting and music.