Russia paraded captive Georgians on armoured vehicles
Russia has rejected a draft UN Security Council resolution on Georgia, saying it contradicted the terms of last week's ceasefire deal.
The draft text called on Russia to pull back its forces to the positions held before the current conflict.
But Russia says the truce allows its troops to stay in a buffer zone on the Georgia side of South Ossetia's border.
Moscow says it is withdrawing its forces from Georgia. An official in the port of Poti said Russians had left.
Russian forces seized the port on Tuesday. But Adam Middleton, the port director, told the BBC Russian troops blew up a naval vessel and took military equipment before withdrawing on Wednesday.
The conflict broke out on 7 August when Georgia launched an assault to wrest back control of the Moscow-backed breakaway region of South Ossetia, triggering a counter-offensive by Russian troops who advanced beyond South Ossetia into Georgia's heartland.
Georgia says its action was in response to continuous provocation.
UK Foreign Secretary David Miliband, who is visiting the region, is to visit a camp for displaced people in Georgia on Wednesday. Tens of thousand of people have been made homeless by the recent conflict.
On Tuesday, Mr Miliband held talks with Georgian President Mikhail Saakashvili in the Georgian capital, Tbilisi, to update him on Nato's reaction at an emergency meeting of foreign ministers in Brussels which demanded that Russia pull its troops out of Georgia.
The foreign secretary criticised Russia's failure to keep to a promise to withdraw troops from Georgia.
Meanwhile, Russia's main security service, the FSB, says a Russian officer has been detained accused of spying for Georgia.
An ethnic Georgian, Mikhail Khachidze was arrested in the southern Russian region of Stavropol near Georgia, an FSB spokesman said.
"[He] was involved in collecting secret information on Russian armed forces, its combat readiness as well as data on other servicemen," he said.
At the UN, Russia's ambassador said the French-drafted UN resolution went against the terms of the ceasefire brokered by France's President Nicolas Sarkozy.
Vitaly Churkin said the resolution should incorporate all elements of the six-point peace plan agreed last week.
He also objected to language in the draft reaffirming Georgia's territorial integrity, saying South Ossetia and Abkhazia did not want to be part of Georgia.
Russia can veto UN resolutions and the ambassador told the BBC that putting the text to a vote would be pointless.
He said: "It's a waste of time because the process of the withdrawal of Russian forces will continue."
HAVE YOUR SAY
As an American, I find Bush's and Rice's comments regarding the attacks on a sovereign nation in the 21st Century just too embarrassing to bear
B Coyle, Maryland
Following a rebuke from Nato's 26 foreign ministers in Brussels, Moscow accused Nato of bias in favour of the "criminal regime" in Tbilisi.
US Secretary of State Condoleezza Rice said Russia risked becoming the "outlaw" of the conflict, in an interview with CBS news on the sidelines of the Nato emergency meeting.
Russia says President Dmitry Medvedev told President Sarkozy that by Friday, Russian troops would either be sent home, be pulled back to South Ossetia or to a buffer zone along the border.
Russia said it had begun a pullback on Tuesday as it withdrew 11 military vehicles from the Georgian town of Gori.
A Russian officer told reporters invited to watch that the column was heading for South Ossetia and then home to Russia, but Georgia dismissed it all as a show.
BBC correspondents there say there are still several artillery positions and checkpoints in Gori.
In an apparent goodwill gesture on Tuesday, the two sides exchanged prisoners at a checkpoint near Tbilisi, but on the same day Russia paraded captive Georgians on armoured vehicles.