Air Force Lt Gen Jeffrey Harrigian, who is in charge of US air operations in the Middle East, says the US has also set up temporary "deconfliction" zones around Syria.
Military operations by Russia or its allies are essentially restricted in those zones so American and US- backed forces are protected.
He declined to say how many exist or where they are. But they signal increased military collaboration as the war on Islamic State militants in Syria escalates.
Disclaimer: No Business Standard Journalist was involved in creation of this content
