28 October 2015, 07:21 GMT
WASHINGTON (Sputnik) — Asked whether the US anti-ISIL campaign has become "more complicated" as result of Russia’s involvement in the region, Allen replied "not really."
"The Russians are operating primarily in the northwest of Syria, and along the spine of Syria, which is well west of most of Daesh [Islamic State]," Allen stated.
Following Russia’s air campaign in Syria that started at the end of September, the United States has slowed its airstrikes in the country, according to data published by the Pentagon.
