In Syria, there is overwhelming evidence of direct US support of Jihadist groups from Al Nusra to ISIS, as shown by the declassified DIA documents and by statements of members from the US establishment.
Recurring pro-Kremlin disinformation narratives about the US supporting or working together with jihadist groups. There is no evidence that US has supported Daesh, al-Nusra or other Jihadist groups in Syria. The US-led military campaign in Syria has been fighting ISIS and Islamic terrorists along with the Global Coalition Against Daesh. Background and a similar case here and here.