"The United States used the February 27 initiative [ceasefire] in order to let an army of many thousands of militants with an enormous stock of weaponry to enter Syrian territory," the ambassador said in an interview.
Earlier in April, Russia requested to add Ahrar ash-Sham and Jaish al-Islam operating in Syria in the Islamic State and al-Qaeda Sanctions List approved by the UN Security Council but the request has been blocked by the United States and other countries.
Syria has been mired in civil war since 2011, with government forces loyal to Syrian President Bashar Assad fighting numerous opposition factions and extremist groups. A US-Russia-brokered ceasefire came into force across Syria on February 27. The ceasefire does not apply to terrorist organizations, such as the Daesh and the Nusra Front, both of which are outlawed in many countries, including Russia.
The Daesh and al-Qaeda are terrorist organizations outlawed in Russia.
