Britain's Foreign Office says Iran's ambassador to London has been called to a meeting to explain supreme leader Ayatollah Ali Khamenei's tirade against the UK.
Khamenei on Friday accused Britain's government of being among the most treacherous of Western powers, repeating frequent complaints about perceived meddling by Britain and others in Iran's affairs.
Britain is one of the six nations involved in negotiations over Iran's nuclear program. The West accuses Teheran of seeking to develop nuclear weapons, a charge Iran denies.
The Foreign Office said the Iranian ambassador will holds talks with political director Mark Lyall Grant later Friday.