Moscow originally promised to begin its pull its forces out of Georgia on August 18, but the West has complained that Russia has not kept its side of the bargain.
So far, only a handful of armored vehicles have left the central Georgian town of Gori, while another column of trucks crossed back into Russia on August 20.
The Russians have countered, however, that they are abiding by the terms of the cease-fire agreed last week, because it allows Russia to carry out "additional security measures" in South Ossetia.
Moscow says that includes a zone extending several kilometers beyond the South Ossetian border into the rest of Georgia.
"The agreement provides for this buffer zone and the advancement of Russian peacekeeping troops in the event of conflict situations," said Colonel General Anatoly Nogovitsyn, the deputy head of Russia's General Staff.
Nogovitsyn said that this means that "we have the right, under certain conditions, to advance to the boundaries of the whole zone of responsibility."
"At the first stage, [we will set up] eight outposts, less than a battalion, 272 men, and later a second line of outposts already along the administrative border of Ossetia, which, of course, need to be equipped from the point of view of engineering and be prepared for providing support to peacekeepers," Nogovitsyn said.
He said Russian troops also have a mandate to operate in a buffer zone around Abkhazia, another separatist Georgian region. Nogovitsyn said that zone includes the key road hub Senaki, where the Georgian military has a military base.
RFE/RL's Georgian Service correspondent in the central town of Gori says that in a meeting with the commander of Russian troops there, the commander presented a map that seemed to show around 50 Georgian villages near Gori, north of the central highway, as being under Russian control. He said this would ensure Russian control of two villages on the main east-west highway.
Against this backdrop, diplomatic tensions flared between Russia and the West at meetings of NATO and the UN Security Council on August 19.
NATO said it was freezing regular contacts with Moscow until all Russian troops leave Georgia. Russia shot back, with Foreign Minister Sergei Lavrov saying NATO was trying to make a victim of Georgia's "criminal regime."
And at the United Nations, Russia rejected a draft resolution calling on it to withdraw is forces to pre-fighting positions, as required by the French-brokered peace deal.
Moscow said the text did not include and endorse the full six-point peace plan signed by Georgia and Russia.
But if the focus of the crisis is now on the Russian troop withdrawal and upon diplomatic sparring, it could shift in the coming hours to events in Georgia's breakaway region of Abkhazia.
On August 20, the Abkhaz parliament voted in favor of asking Russia to recognize the province as an independent state.
Georgian Reintegration Minister Temur Iakobashvili dismissed the appeal as meaningless.
But in Moscow, the speaker of Russia's upper house of parliament, the Federation Council, said on August 20 that lawmakers are ready to recognize the independence of separatist regions in Georgia. The council is to hold an emergency session on August 25.
All this sets the stage for yet another escalation of tensions in the Georgia crisis. Both Abkhazia and South Ossetia are officially recognized internationally, including by Russia, as part of Georgia.
President Dmitry Medvedev reportedly told French President Nicolas Sarkozy, whose country holds the rotating EU Presidency, in a telephone conversation on August 19 that all but 500 Russian troops would be pulled out of Georgia over the next two days.
RFE/RL's Georgian Service correspondent in Gori says the number of Russian troops and military vehicles was down overnight but adds that it's too early to tell whether it will lead to a withdrawal.
A local official in Gori quoted the Russian commander of forces in the area, Major General Vyacheslav Borisov, as telling him that seven checkpoints will remain ahead of a pullout by August 22.
"We are dealing with equipment in the security zones," Borisov told RFE/RL. "We already started leaving -- a long time ago. Those [Russian forces] in [the South Ossetian capital] Tskhinvali, they're already going back. We [forces in the Gori area] entered first, so we have to be last to go. We've abolished quite a few checkpoints."
Russian naval infantry also hold Georgia's key Black Sea port of Poti. In the occupied areas, the troops continue to dismantle or destroy Georgian military infrastructure.
with additional agency reporting