Britain has appointed an ambassador to Iran for the first time since 2011 amid improved relations between the two countries.
Nicholas Hopton, a former British ambassador to Yemen and Qatar, will take up the role. He had previously been serving in a lower position at the British Embassy in Tehran.
The announcement by the Foreign Office comes one year after the reopening of the British Embassy in Tehran, which was closed in November 2011 after being stormed and ransacked by a group of protesters.
"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," Foreign Secretary Boris Johnson said in a statement.
"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," the statement added.
The decision follows last week's resumption of direct British Airways flights between London and Tehran.
Iran's ties with Western countries have improved following last year's nuclear deal under which Tehran has significantly limited its nuclear program in exchange for sanctions relief.