LONDON (AFP) - Britain's new envoy to Teheran visited Iran on Tuesday, becoming the first British diplomat to travel to the country since ties were severed in 2011, the Foreign Office in London said.

Mr Ajay Sharma, who is making his first trip in his new role as non-resident charge d'affaires, held "detailed and constructive" talks with his Iranian counterpart Hassan Habibollah-Zadeh and other officials.

"I had a good first visit back to Tehran today and want to thank the Iranian authorities, particularly my counterpart Mr Habibollahzadeh, for facilitating the trip," Mr Sharma said in a statement issued by the Foreign Office.

"I held detailed and constructive discussions with the Iranian Ministry of Foreign Affairs about taking forward our bilateral relationship on a step-by-step and reciprocal basis."

Mr Sharma said he also visited the British embassy compounds "to assess the damage caused" in November 2011 when they were stormed by hundreds of Islamist students, prompting Britain to shut the embassy and sever diplomatic ties.

The students - protesting against Western sanctions over Iran's disputed nuclear programme - ransacked the building as well as the British ambassador's residence in north Teheran.

The two countries each named a non-resident charge d'affaires - a diplomatic post that is one level below ambassador - last month.

"I intend to visit Iran regularly to continue the step by step process of improving relations between our two countries," Mr Sharma said.