A US think tank says Russian President Vladimir Putin's mobilization of reserves is, "unlikely to decisively impact the country's combat power."

The Institute for the Study of War released an assessment on Friday.

It says, "Russia's deployment of 41,000 poorly trained combat personnel to Ukraine may have temporarily stiffened Russian defense lines but these reserves have not yet faced the full weight of a major and prepared Ukrainian counteroffensive thrust."

It also says a total of 150,000 mobilized personnel will be deployed to combat roles in November but believes additional mobilization of combat units, "remains unlikely to change the trajectory of the war. "

The assessment also mentions Putin ending mobilization. It says the decision was made to, "free up training capacity in time for the delayed start of the Russian autumn conscription cycle, which will begin on November 1".

It says, "Russia's military likely does not have the capacity to simultaneously support training of troops who have been mobilized and 120,000 new autumn conscripts."