Sergei Lavrov said the US had broken its promise to separate the powerful Jabhat Fateh al-Sham (formerly known as al-Nusra Front) and other extremist groups from more moderate rebels.
And he defended the bombardment of Aleppo by Russian and Syrian forces.
Jabhat Fateh al-Sham is linked to al-Qaeda.
Mr Lavrov was speaking to Stephen Sackur on BBC World News TV on the first anniversary of the beginning of the Russian air campaign in Syria.
"They [the US] pledged solemnly to take as a priority an obligation to separate the opposition from Nusra," he said.