Russian efforts in fight against IS 'virtually zero': Pentagon

Russia has given "virtually zero" support to the United States in fighting the Islamic State group in Syria and Iraq, US Defence Secretary Ash Carter said on Sunday.

Moscow had promised to help fight extremists and help end the Syrian civil war by urging President Bashar al-Assad to stand aside, Carter told NBC's "Meet the Press", but instead Russia "doubled down on the Syrian civil war".

"They haven't done anything," he added.

"They came in, they said they were going to fight ISIL, and they said they were going to help in the civil war in Syria," he said, using another acronym for the hardline Sunni group.

"They haven't done either of those things. As a consequence of course, we're fighting ISIL ourselves," he added.

Russia's involvement in the Syrian conflict since it began its military intervention in September 2015 has centred boosting regime forces in retaking rebel areas such as Aleppo and Idlib.

However Carter's comments come a few days after three Russian jets took part in Turkey's Operation Euphrates Shield by striking IS positions which are under attack from Turkish and Syrian rebel fighters, with the recent Russian-Turkish-Iranian brokered ceasefire agreement seeming to have created a new phase in the war.