Iran and Britain officially resumed Thursday diplomatic relations severed by London after students stormed its Tehran embassy in 2011, a senior Iranian official said.

Iran and Britain officially resumed Thursday diplomatic relations severed by London after students stormed its Tehran embassy in 2011, a senior Iranian official said.

"From today relations between Iran and Britain are resumed at the non-resident charges d'affaires level," Deputy Foreign Minister Majid Takht-Ravanchi told ISNA, adding that the countries' flags were raised atop their embassies in Tehran and London.

The British Foreign Office sent a tweet saying "today the UK ceased formal Protecting Power arrangements in Iran. We will now conduct relations directly through non-resident charges" d'affaires.

In November, the two countries had already named those non-residents, and Britain's new envoy, Ajay Sharma, visited Iran in December.