However, Russian soldiers took Georgian servicemen prisoner in Poti and commandeered the U.S. Humvees. An Associated Press photographer saw Russian trucks and armored personnel carriers leaving the port with about 20 blindfolded and handcuffed men riding on them.
Port spokesman Eduard Mashevoriani said the men were Georgian soldiers.
Pentagon spokesman Bryan Whitman said officials were looking into the reported theft of the Humvees.
The deputy head of Russia's general staff, Col. Gen. Anatoly Nogovitsyn, said Russian forces plan to remain in Poti until a local administration is formed, but did not give further details. He also justified previous seizures of Georgian soldiers as necessary to crack down on soldiers who were "out of any kind of control ... acting without command."
An AP television crew has seen Russian troops in and around Poti all week, with local port officials saying the Russians had destroyed radar, boats and other Coast Guard equipment there.
Russian troops last week drove Georgian forces out of South Ossetia, where Georgia on Aug. 7 launched a heavy artillery barrage in the separatist Georgian province with close ties to Russia. Fighting also has flared in a second Russian-backed separatist region, Abkhazia.
The short war has driven tensions between Russia and the West to some of their highest levels since the breakup of the Soviet Union, but Russian President Dmitry Medvedev has icily defended Russia's actions.
"Anyone who tries anything like that will face a crushing response," he said Monday. Later Medvedev handed out military medals to Russian soldiers involved in the fighting.
The cease-fire requires both sides to return to positions held before the fighting began, but Whitman said Tuesday morning in Washington that it didn't appear Russia had made any significant withdrawal of forces.
"So far we have not seen any significant movement out of Georgia," he said.
A small column of Russian tanks and armored vehicles left Gori on Tuesday, and a Russian officer said they were heading back to South Ossetia and then Russia. Col. Igor Konoshenkov, a Russian military officer at the scene, gave no timetable for when the unit would reach Russia.
Also Tuesday, Russia and Georgia exchanged 20 prisoners of war in an effort to reduce tensions. Two Russian military helicopters landed in the village of Igoeti, the closest that Russian forces have advanced to the Georgian capital of Tbilisi. Soldiers and men in unmarked clothing got off and two people in stretchers were taken to Georgian officials.
Georgian ambulances later brought two other people to the Russian choppers. One was on a gurney.
Georgian Security Council head Alexander Lomaia told reporters in Igoeti that 15 Georgians and five Russians were exchanged. "It went smoothly," he said. The operation also witnessed by Russian Maj. Gen. Vyacheslav Borisov, who commands troops in the area. Lomaia said the exchange removed any pretext for Russians to keep holding positions in Igoeti, 30 miles west of Tbilisi, or anywhere else on Georgia's only significant east-west highway.
In Brussels, Secretary of State Condoleezza Rice was backing the setting up of a permanent NATO-Georgia Commission to solidify ties between the Western alliance and Georgia. Diplomats said Washington also supports increasing training for the Georgian military.
At the same time, NATO foreign ministers were discussing possibly scaling back high-level meetings and military cooperation with Russia if it does not abandon crucial positions across Georgia. But there were differences within the alliance over how far to go in punishing Moscow.
At a separate meeting, the Organization for Security and Cooperation in Europe said Russia agreed to allow 20 more international military monitors in and around South Ossetia. Finnish Foreign Minister Alexander Stubb says the plan calls for the observers to be sent immediately to Tbilisi. The group already has nine observers based in South Ossetia.
The United Nations has estimated that the fighting displaced more than 158,000 people. U.N. refugee chief Antonio Guterres arrived in Tbilisi on Tuesday to meet with government representatives to discuss the plight of tens of thousands of South Ossetians uprooted by Georgia's conflict with Russia.
Guterres then will travel to Moscow to meet with Russian officials, U.N. High Commissioner for Refugees spokesman Andrej Mahecic said.
Mahecic told journalists in Geneva that UNHCR, like other aid agencies, has not been able to reach the civilian population in much of South Ossetia because of security issues there. The area is now controlled by Russia.
"We have seen media reports indicating that people are being shot at while trying to leave the area," he said.
In Gori, most shops were shut and people milled around on the central square with its statue of the Soviet dictator and native son Josef Stalin.
"The city is a cold place now. People are fearful," said Nona Khizanishvili, 44, who fled Gori a week ago for an outlying village and returned Monday, trying to reach her son in Tbilisi.
Associated Press writers David Nowak, Jim Heintz and Steve Gutterman in Moscow, and Christopher Torchia in Igoeti, Georgia, contributed to this report.