"Experts say that there is an explanation. Moderate or not moderate rebels are not the issue," he wrote for RIA Novosti. "The question is who has been trapped in Aleppo. Experts say that there are approximately 200 Western instructors."
The United States suspended "its participation in bilateral channels with Russia that were established to sustain the cessation of hostilities" on Monday, US State Department spokesman John Kirby said in a statement.
Both Kirby and Earnest accused Moscow of failing to fulfil its part of the deal negotiated by Russian Foreign Secretary Sergei Lavrov and US Secretary of State John Kerry. The agreement was seen as a major step forward to a lasting peace in Syria, but it was derailed due to hundreds of ceasefire violations by US-backed rebels.
Earnest further assumed that Russian officials "have been reduced to try and to claim credit for successful US operations" in Syria.
Referencing the killing of Daesh's top commander Abu Muhammad al-Adnani, he said that "Russia was in a position where they were rather pathetically trying to claim credit for having carried out that operation. I think that's an indication that they don't have much to claim credit for when it comes to fighting extremists and fighting [Daesh]."
Russian Ambassador to the UN Vitaly Churkin described Earnest's assertions as "indelicacy, to put it mildly."
Russia has been hailed for its limited, but efficient military operation in Syria that has helped Damascus-led forces to turn the tide of the five-and-a-half-year war, recover key cities and boost the SAA's morale. Moscow has also been credited for its diplomatic efforts to launch an inclusive dialogue aimed at finding a suitable and lasting resolution to the conflict that has claimed more than 280,000 lives and displaced a half of Syria's population.