British Foreign Secretary Boris Johnson was not setting out government policy when he said Saudi Arabia and Iran were stoking proxy wars across the Middle East, a spokeswoman for Prime Minister Theresa May said on Thursday.

Johnson, known for his colorful use of language and tendency to go off-script, told an audience in Rome last week that the absence of real leadership in the Middle East had allowed people to twist religion and stoke proxy wars.

It is the latest in a series of gaffes to plague the foreign minister, who even May has jokingly said is hard to keep "on message for a full four days." He has been criticized by some EU officials for using less-than-diplomatic language in talks on Britain's decision to leave the bloc.