Karloff said:
State-owned Russian television reported that the meteorites had been engaged and shot down by local air defence forces, but this was contradicted later by Prime Minister Dmitry Medvedev, who said that neither Russia nor the United States had the capability to do so.
Actually its not entirely impossible the US could hit an Asteroid that large, The Russians probably could too. So could China and maybe India and a few other countries. All have a layered ballistic missile defense system that can hit objects of that size at that altitude and travelling at that speed. The issue here seems to be more about initial detection rather than being unable to engage the meteorite.
For example the Russian A-135 (not sure if NATO or Russian designation) system fires long range exoatmospheric missiles that travel at around Mach 4 and a secondary set of endoatmosperhic missiles that accelerates to Mach 10 in around 5 seconds. Both are linked to a fire control system of phased array RADAR stations and redundant command facilities, they can control an estimated 12-16 missiles at any single point in time.
The Russian system only really covers Moscow though (to the best of public knowledge) so even if they had prior warning they probably wouldn't have been able to do anything about it. Theoretically though if that rock had came close enough they could have fired at it, the meteorite wasn't that big either so they might have been able to break it up too.