The UK has upgraded its diplomatic relations with Iran, appointing an ambassador to the Islamic Republic for the first time in five years. The role will be taken by Nicholas Hopton, formerly the British Chargé d'affaires in Tehran, and the move comes a year after the British Embassy in Tehran was reopened and nine months since the implementation of the Iran nuclear deal.

UK foreign secretary Boris Johnson said: "This is an important moment in the relationship between the UK and Iran.

"The upgrade in diplomatic relations gives us the opportunity to develop our discussions on a range of issues, including our consular cases about which I am deeply concerned, and which I have raised with foreign minister Zarif."

The UK's decision to upgrade relations with Iran comes as several Middle Eastern countries have announced they have severed ties with the Islamic Republic, including Jordan, Bahrain, Kuwait, Qatar, Saudi Arabia and Sudan.

Saudi Arabia announced it would cut diplomatic ties with Iran in January after its embassy in Tehran was attacked following the execution of popular Shia cleric Nimr al-Nimr, an incident that underscored the fractious relationship between the two nations.

However, since the signing of the nuclear deal, western countries including the UK have seen relations with Iran improve.

Johnson added: "I hope this will mark the start of more productive cooperation between our countries, enabling us to discuss more directly issues such as human rights and Iran's role in the region, as well as ongoing implementation of the nuclear deal and the expansion of the trading relationship between both our countries."