In an exclusive interview with the BBC, Russian Foreign Minister Sergei Lavrov says his country believes the United States may be tacitly supporting jihadist rebels in Syria.

He said the US had broken a promise to help separate the the powerful Jabhat Fateh al-Sham (formerly known as al-Nusra Front) and other extremist groups from more moderate rebels.

He was speaking to Stephen Sackur on BBC World News TV on the first anniversary of the beginning of the Russian air campaign in Syria.