"Russia conducted 20 bombing missions in Damascus and Eastern Ghouta the week of February 24. Now, Russia is also using Syria to test SU-57 stealth fighter. So much for Russia’s commitment to the ceasefire, civilian safety, and humanitarian assistance. Astana has failed," Nauert said in a Twitter message.
This is not the first time, the US State Department dubs the Astana process as "failure."
Last month, the UNSC unanimously approved resolution 2401, which provides for the introduction of a ceasefire regime throughout Syria for a period of 30 days.
The decision on the resolution came nearly two weeks after the escalation of the situation in Eastern Ghouta, following the launch of a military operation by the Syrian government forces, in a bid to clear the region of militants.
READ MORE: Russian Embassy Slams US State Dept. Statements on Astana Syrian Peace Process
Despite the ceasefire, regime militants continued to shell Damascus, with Russian President Vladimir Putin saying that terrorists in Eastern Ghouta had been shelling Damascus around 50-80 times a day, including the region of Russia’s embassy.
However, the US State Department instantly shifted the blame on Damascus, saying that the Syrian forces been conducting airstrikes in Eastern Ghouta, that had claimed lives of civilians.