The international conference in Geneva starting on Wednesday will focus on future security arrangements for Georgia's rebel republics, recognized as independent by Russia, and the situation in the region as a whole after Russia's five-day war with Georgia, which attacked South Ossetia in early August.
"Our position on the issue is clear and unchanging - without Abkhazia and South Ossetia, it will be impossible to reach any agreement on their security," Andrei Nesterenko said.
French Foreign Minister Bernard Kouchner, whose country currently holds the European Union presidency, said on Monday that representatives from South Ossetia and Abkhazia "will most probably participate in the talks as the Russians requested."
Nesterenko also said the two republics, which Russia recognized as independent on August 26, would seek legal security guarantees, including agreements not to use force with Georgia, and that Russia is seeking detailed security regulations in areas adjacent to the breakaway regions.
The spokesman reiterated Moscow's earlier appeals for an embargo on offensive and heavy weapons to Georgia to prevent a new wave of the Caucasus state's "unrestrained militarization."
Georgia's ally the United States and other Western countries are expected to look into Russia's compliance with its withdrawal commitment under the French-brokered ceasefire agreement with Georgia at talks in Geneva.
The State Department said on Tuesday the U.S. still had "serious concerns" over the Russian troops' location and their overall numbers in the separatist regions.
State Department spokesman Sean McCormack said: "There are still open question. I would expect that the issues of geography that we've talked about as well as issues of overall numbers that we talked about are going to be front and center during those October 15th discussions."
Russia reported a complete pullout from Georgian territory ahead of the October 10 deadline. Its troops have been replaced by a EU monitoring mission.
Tbilisi has objected to Russia's military presence in the upper Kodori Gorge and the Akhalgori district, while Moscow says the areas are the parts of Abkhazia and South Ossetia that had been occupied by Georgian troops.