Russian Foreign Minister Sergei Lavrov on Wednesday accused the United States and its allies of orchestrating "deadly provocations" against Russian troops in Syria.
Moscow has complained about what it has says are suspiciously friendly ties between US-backed militias, US special forces, and Islamic State in Syria and accused Washington of trying to slow the advance of the Syrian army.
"There are a lot of questions to US-led forces in Syria," Lavrov told pan-Arab newspaper Asharq al-Awsat in an interview published on Wednesday.
"Either they accidentally bomb Syrian troops after which Islamic State militants launch an offensive, or they get other terrorists to attack strategically important objects ... or they stage deadly provocations against our military servicemen."
Lavrov's deputy, Sergei Ryabkov, said last week that the "two-faced policy" of the United States was to blame for the death of Russian Lieutenant-General Valery Asapov in Syria, something Washington flatly denied.
Asapov was killed by Islamic State shelling.
Lavrov also said on Wednesday that the United States and the coalition it leads were "unwelcome guests" in Syria from the point of view of international law and accused Washington of "dividing terrorists into bad and no so bad ones".