London, Reuters—Britain plans to re-open its embassy in Iran, British Foreign Secretary William Hague said on Tuesday, saying it would soon establish a small initial presence in Tehran two and a half years after a mob ransacked its embassy there.

The announcement comes after the United States, a close ally of Britain, said it could launch air strikes and act jointly with its arch-enemy, Iran, to shore up the Iraqi government after a rampage by Sunni Islamist insurgents across Iraq that has scrambled alliances in the Middle East.

“I have . . . now decided the circumstances are right to reopen our embassy in Tehran,” Hague said in a written statement to parliament. Hague said he had discussed the matter with Iranian Foreign Minister Mohammad Javad Zarif on Saturday.

Britain closed its Tehran embassy in late 2011 after a protest against British sanctions became violent and protesters scaled the walls, ransacked offices and burned buildings.

Diplomatic ties were revived in November last year when Britain appointed a non-resident chargé d’affaires as Iran and the five permanent members of the UN Security Council plus Germany reached an interim deal over Iran’s contested nuclear program.

Hague described Iran an “an important country in a volatile region” and stressed the need for embassy staff to be able to work without hindrance in Tehran. Once a range of practical issues had been resolved he said the embassy would resume operations with a small initial presence.