Darko Bandic, Associated Press
Russian vehicles move Saturday in Orjosani, between Tbilisi and strategic town of Gori. Russia says it will take as long "as needed" to ensure effective security.

IGOETI, Georgia — Russian forces built ramparts around tanks and posted sentries on a hill in central Georgia on Saturday, digging in despite Western pressure for Moscow to withdraw its forces under a cease-fire deal signed by Russian President Dmitry Medvedev.

The United States and France said it appeared Russia was defying the truce already. Russian troops still controlled two Georgian cities and the key east-west highway between them Saturday, cities well outside the breakaway provinces where earlier fighting was focused.

"From my point of view — and I am in contact with the French — the Russians are perhaps already not honoring their word," U.S. Secretary of State Condoleezza Rice said.

Russia's foreign minister, Sergey Lavrov, said Medvedev had signed the cease-fire deal and ordered its implementation but would not withdraw troops until Moscow is satisfied that security measures allowed under the agreement are effective. He said Russia would strengthen its peacekeeping contingent in South Ossetia, the separatist Georgian region at the center of more than a week of warfare that sharply soured relations between Moscow and the West.

Asked how much time it would take, he responded: "As much as is needed."

President Bush warned Russia Saturday that it cannot lay claim to the two separatist regions in U.S.-backed Georgia even though their sympathies lie with Moscow. "There is no room for debate on this matter," the president, with Rice, told reporters at his Texas ranch.

Later Saturday, Georgia's Foreign Ministry accused Russian army units and separatist fighters in one of the regions, Abkhazia, of taking over 13 villages and the Inguri hydropower plant, shifting the border of the Black sea province toward the Inguri River.

Abkhaz officials could not immediately be reached for comment on the late-night claim, and there was no information on whether the seizure involved violence.

The villages and plant are in a U.N.-established buffer zone on Abkhazia's edge, and it appeared that the separatists were bolstering their control over the zone after Russian-backed fighters forced Georgians out of their last stronghold in Abkhazia earlier this week.

The tense peace pact in Georgia, a U.S. ally that has emerged as a proxy for conflict between an emboldened Russia and the West, calls for both Russian and Georgian forces to pull back to positions they held before fighting erupted Aug. 7 in the other breakaway province, South Ossetia in central Georgia.

But freshly dug positions of Russian armor in the town of Igoeti, about 30 miles west of the capital Tbilisi, showed that Russia was observing the truce at the pace and scope of its choosing.

Rice noted that the text of the cease-fire agreement, negotiated by French President Nicolas Sarkozy, the current leader of the European Union, outlined a very limited mandate only for Russian peacekeepers who were in Georgia at the time hostilities escalated. She said the agreement specifies that these initial peacekeepers can have limited patrols in a prescribed area within the conflict zone and would not be allowed to go into Georgian urban areas or tie up a cross-country highway.

According to Rice, Medvedev told Sarkozy that the minute the Georgian president signed the cease-fire agreement, Russian forces would begin to withdraw.

Sarkozy said Saturday that the truce explicitly bars Russian troops from Gori or "any major urban area" of Georgia.

Earlier Saturday, Russian forces dug shallow foxholes in the middle of Igoeti and parked tanks, one flying a Russian flag, along the road. In the afternoon, they withdrew from those positions to the town's western outskirts. There, they set up defensive positions with tank cannons pointed back toward Georgian-held territory, where police and soldiers milled about, awaiting Russia's next move.

West of Igoeti, Russian troops were deployed in large numbers in and around the strategic city of Gori, which endured an intense Russian bombardment during the fighting that began when Georgia attacked its breakaway region of South Ossetia. Military vehicles on the side of the road were camouflaged with branches; a couple of soldiers slept on stretchers in the shade of the hulking machines.

Russian troops effectively control the main artery running through the western half of Georgia, because they surround the strategic central city of Gori and the city and air base of Senaki in the west. Both cities sit on the main east-west highway that slices through two Georgian mountain ranges.

Controlling Senaki, which sits on a key intersection, also means the Russians control access to the Black Sea port city of Poti and the road north to Abkhazia. AP reporters have seen Russian troops there for days but noted a growing contingent Saturday and artillery guns and tanks pointed out from the city, which they appear to be using as a base for their sorties elsewhere in western Georgia.

An Associated Press Television News team saw Russian soldiers pulling out of the Black Sea port of Poti Saturday after sinking Georgian naval vessels and ransacking the port. A picture of Georgian President Mikhail Saakashvili in the looted office of the Navy and Coast Guard had been vandalized, with the face scratched out.

"They have robbed the military base and taken almost everything, and they have burned or sunk the stuff they could not carry," port worker Zurab Simonia said.

Lavrov was not specific about the security measures planned, but suggested they would be limited mostly to South Ossetia, not Georgia proper. He accused Georgia of undermining security, citing the Russian military's claim that it had averted an attack on a highway tunnel by stopping a car laden with grenade launchers and ammunition.

"We are constantly encountering problems from the Georgian side, and everything will depend on how effectively and quickly these problems are resolved," he said.

Georgia, meanwhile, claimed that Russian forces blew up a railroad bridge Saturday. Russia denied it.

The rival claims underscored the fragility of the cease-fire. Lavrov said the deal Saakashvili signed Friday differed from the one with Medvedev's signature, with Saakashvili's version lacking an introductory preamble. While that difference may appear to be a technicality, it could be one either side could cite if it wants to abandon the deal.

The conflict erupted after Georgia launched a massive barrage to try to take control of South Ossetia. The Russian army quickly overwhelmed its neighbor's forces and drove deep into Georgia, raising fears that it was planning on a long-term occupation.

Even if Russian forces do withdraw from the rest of Georgia, Moscow appears likely to maintain strong control over South Ossetia. Lavrov said Thursday that Georgia can "forget about" South Ossetia and Abkhazia, which broke from Georgian government control in early 1990s wars, and their future status is shaping up as a potentially explosive source of tension.