AKHMAJI, Georgia – At a military checkpoint between Georgia and its breakaway region of South Ossetia, the word "Russia" is hand-painted in pink on a concrete security barrier.

"It will be Russia," said a Russian army lieutenant as the Ossetian soldiers under his command nodded.

"And Georgia used to be Russian, too," said the young freckle-faced lieutenant, who would give only his first name, Sergei. Three armored personnel carriers and a tank were dug in around the checkpoint.

Russia has troops just 25 miles (40 kilometers) from the Georgian capital, in violation of the European Union-brokered cease-fire that ended last year's brief war. And in recent weeks, it has put even more soldiers and armored vehicles within striking distance of the city ahead of street protests against Georgia's president.

The protests, which began April 9, drew about 10,000 people Tuesday, and opposition leaders said they would continue daily until President Mikhail Saakashvili resigned.

The demonstrations have been fed by public anger over Georgia's humiliating defeat in the August war, which left Russian troops on previously Georgian-controlled territory and drove tens of thousands of Georgians from their homes.

By reinforcing its military presence at a time of potential political instability, Russia appears determined to maintain pressure on Saakashvili, whom Moscow has openly said must be replaced before relations can be repaired.

Georgia's Western-leaning government accuses the Kremlin of hoping to capitalize on political unrest to restore its influence over the former Soviet republic, which for almost 200 years was ruled by Moscow.

The presence of the Russian troops poses a dilemma for Washington as it aims to improve relations with Moscow. Georgia worries the Obama administration will be reluctant to pressure Russia to comply with the cease-fire while seeking its cooperation on priority issues like the war in Afghanistan and North Korea's nuclear weapons program.

Tensions over Georgia also complicate efforts to restore ties between Russia and NATO, which broke off contacts following the war. Russia has strongly objected to NATO military exercises scheduled to begin May 6 in Georgia and has warned the U.S. against helping Georgia rebuild its army.

The military checkpoint near Akhmaji enforces a new boundary between Georgia and South Ossetia, the Russian-supported region that was at the center of the fighting. After routing the Georgian army, Russian troops took over entire districts of South Ossetia that had long been under Georgian control.

Russian forces also occupied a new swath of territory in a second breakaway republic, Abkhazia, along the Black Sea coast.

The European Union and United States consider Russia in violation of the cease-fire signed by President Dmitry Medvedev, which called for troops to pull back to positions held before the war began.

Russia says the cease-fire has been superseded by separate agreements it signed with South Ossetia and Abkhazia, which Moscow now recognizes as independent states.

The actions by Russia reflect both its military strength and its willingness to challenge the West to reclaim a dominant role in Georgia and elsewhere in its former sphere of influence.

Georgia's government sees Russia as determined to prevent the West from considering Georgia a reliable transit country for oil and natural gas, contending that was Russia's main objective in the war.

The pipelines that cross Georgian territory are among the few that bypass Russia in supplying Europe with energy from the Caspian Sea and Central Asia. During the war, Russia bombed areas near the pipelines.

"Russia wants to be the monopoly supplier," said political analyst Shalva Pichkhadze.

Russia's Foreign Ministry confirmed the Kremlin has sent reinforcements to the boundary lines. It was responding to fears the Georgian government would provoke clashes to distract from the opposition protests, ministry spokesman Andrei Nesterenko said.

Georgia's Interior Ministry said Russia has 15,000 soldiers in South Ossetia and Abkhazia, which would be far more than in past months. Since the beginning of April, Russia has moved 130 armored vehicles toward the boundary line from elsewhere in South Ossetia and 70 more have entered South Ossetia from Russia, ministry spokesman Shota Utiashvili said.

Russia's Defense Ministry refused to comment on the composition of its forces, and Georgia's claims could not be independently verified. European monitors who patrol the boundary lines are not allowed into South Ossetia or Abkhazia, and journalists also are stopped at Russian checkpoints.

Peter Semneby, the EU special representative for the South Caucasus, said the Russian military presence is clearly "significantly larger" than it was.

From a Georgian police checkpoint just 100 yards (meters) from a Russian roadblock controlling access to the village of Akhmaji, a half dozen Russian tanks and other armored vehicles can be seen in the valley.

Local police chief Timur Burduli said the vehicles appeared during the first week of April and are the Russian forces closest to Tbilisi, the Georgian capital. "A tank needs only 40 minutes," he said.

Along the highway to Tbilisi, a freshly dug anti-tank trench stretches across a long field. Steve Bird, spokesman for the EU monitors, said the Georgians have been building such defenses in recent weeks.