MOSCOW (Reuters) - The head of the Russian Orthodox Church, Patriarch Kirill, will meet Britain's Queen Elizabeth during a visit to London this weekend, Russia's TASS news agency reported on Thursday.

The meeting between Kirill and Queen Elizabeth, who is Supreme Governor of the Church of England, comes at a time when relations between London and Moscow are strained over Syria and the Ukraine crisis.

British Foreign Secretary Boris Johnson said on Tuesday Russia risked becoming a "pariah nation" and accused it of targeting civilians in Syria. He called for protests outside the Russian embassy in London.

Moscow has denied striking civilian targets and said Johnson's comments amounted to "Russophobic hysteria".

(Reporting by Jack Stubbs; Editing by Andrew Osborn)