A Russian Foreign Ministry official said on Thursday the entry of Ukraine and Georgia into NATO would be a "huge strategic mistake" after alliance leaders pledged to offer them membership one day, according to Reuters.

But in a less strident reaction, Russia`s envoy to NATO said a decision by the alliance to review the progress of the two former Soviet republics again in December would change nothing.

NATO leaders failed to offer Ukraine and Georgia a Membership Action Plan (MAP)-- a gateway to possible entry -- at a summit in Bucharest on Wednesday, but agreed on Thursday to let them join the defense alliance one day.