"The formations of terrorist organizations Jabhat al-Nusra and ISIS [Daesh] continue to hinder the establishment of the ceasefire regime [in Syria]," the statement, published by the Russian Defense Ministry, says.
Syria has been mired in civil war since 2011, with government forces loyal to President Bashar Assad fighting a number of opposition factions and extremist groups, such as Daesh and Jabhat Fatah al Sham, both of which are banned in Russia and a range of other countries.
On September 9, Russian Foreign Minister Sergey Lavrov and US Secretary of State John Kerry presented a new plan to regulate the conflict in Syria, which included a new ceasefire that came into force on September 12.
On Wednesday, Lavrov stressed that the September 16 attacks by US-led coalition forces on Syrian army positions at a military airport near Deir ez-Zor were a flagrant violation of the ceasefire agreement. According to the Russian Foreign Ministry, the new ceasefire in Syria has been strictly adhered to only by the Syrian government forces.