A senior adviser to Iran’s supreme leader indicated on Tuesday that Tehran could look favourably on the recent international offer put to it, describing the proposal as acceptable “in principle”.

Ali-Akbar Velayati, a former foreign minister who advises Ayatollah Ali Khamenei, Iran’s top leader, on international issues, said it was “expedient” for Iran to resume nuclear negotiations on the offer made by the five permanent members of the United Nations Security Council plus Germany.