The United States has warned of "additional steps" if Damascus continues taking actions against the US-backed militants in crisis-hit Syria.
At the Monday news briefing, White House spokesman Josh Earnest was referring to US-trained militants, who he admitted have been suffering losses.
Earnest said that the government of President Bashar al-Assad "should not interfere" in operations by the US-backed forces on the Syrian soil, which he alleged were part of a "strategy to degrade and ultimately destroy ISIL" as US President Barack Obama had promised.
Syria has been battered by foreign-backed militancy since 2011, which made it a haven for Takfiri terrorists to come together as ISIL.
ISIL has been used as a pretext by Washington and some of allies to carry out airstrikes in the country apart from providing various forms of support for the so-called moderate militants there.
In response to Earnest’s remarks, Russian Foreign Minister Sergei Lavrov said Moscow believes “it's counterproductive to announce publicly that some US-trained armed groups... will be under the protection of the coalition's air forces."
"And that to protect these groups this air force would be authorized to strike at any forces which may -- may -- be considered a hindrance to the work of this group," he said a at a news conference in the Qatari capital Doha, where he met with US Secretary of State John Kerry earlier in the day.
Lavrov said he had raised the issue with Kerry in that meeting.