According to a statement released from Prime Minister's Office-10 Downing Street that on Tuesday afternoon, Cameron and Iranian President Hassan Rouhani discussed Iran's nuclear programme in a phone call ahead of today's nuclear negotiations in Geneva which made Cameron to become the first British prime minister to call an Iranian president in more than a decade. Downing Street spokesperson noted that two leaders discussed bilateral relationships between the UK and Iran welcoming the steps taken since President Rouhani took office, including the appointment of non-resident charges d'affaires last week. It was added that Cameron and Rouhani agreed to continue efforts to improve the UK-Iran relationships on a step by step and reciprocal basis. Touching onto Iran's nuclear programme, spokesperson expressed that both Cameron and Rouhan agreed that "significant progress had been made in the recent Geneva negotiations" and that it was "important to seize the opportunity presented by the further round of talks" which will kick off today. "The Prime Minister underlined that Iran should address the concerns of the international community about their nuclear programme comprehensively, including the need for greater transparency", number 10 added.

Iran will once more sit around the table with the five permanent members of the UN Security Council -UK, France, Russia, China and the United States- plus Germany in Switzerland's Geneva today. Earlier in November, the previous round of high-level talks about Iran's nuclear programme lasted 3 days failing to achieve a breakthrough.

Furthermore, last week Ajay Sharma was appointed the United Kingdom's non-resident charge d'affaires to Iran.

British and Iranian embassies have remained closed since 2011, when protesters in the Iranian capital stormed the British Embassy during a demonstration against British sanctions on Iran.