Dmitry Rogozin, Russia's envoy to the alliance, said on Thursday that in making its decision on Ukraine, NATO had taken into account the fact that the majority of the country's population was opposed to NATO membership.
As for Georgia, he continued, countries with "blurry" borders are not admitted to NATO, since the North Atlantic alliance "does not consider it appropriate to have to deal with Georgia's territorial disputes."
Georgia does not fully control its territory due to so-called frozen conflicts in its breakaway republics of Abkhazia and South Ossetia, both of which have recently appealed to Russia for recognition.
For countries to join MAP, a precursor to membership in the military alliance, all 26 allies must give their approval. However, concerns voiced by France and Germany that bringing Russia's neighbors into the alliance would unnecessarily provoke Moscow seem to have swung the argument in favor of the 'no' camp.
Moscow has consistently expressed its opposition to membership of NATO for neighboring Ukraine and Georgia. Russian President Vladimir Putin had earlier threatened to retarget Russian missiles at Kiev if Ukraine joined the alliance.
U.S. President George Bush had campaigned strongly for MAP for Ukraine and Georgia, visiting Kiev on the eve of the Bucharest summit for talks with Ukraine's president, Viktor Yushchenko.
"My country's position is clear - NATO should welcome Georgia and Ukraine into the Membership Action Plan," Bush said.
He also looked to assuage Russia's fear of NATO's possible eastward expansion, saying, "The Cold War is over. Russia is not our enemy. We are looking to a new security relationship with Russia."
The secretary general of the North Atlantic alliance said however that Ukraine and Georgia would eventually become NATO members.
Jaap de Hoop Scheffer said NATO leaders endorsed Ukraine and Georgia's accession to the Membership Action Plan, but that NATO would reconsider Georgia and Ukraine's bid to join MAP in December.
President Putin is set to arrive in Bucharest later today to attend the NATO summit as a guest.