Russia has said that Georgia is preparing to invade the breakaway region of Abkhazia.
A statement from the Russian foreign ministry said that "a bridgehead is being prepared for the start of military operations against Abkhazia".
Russia accuses Georgia of amassing 1,500 soldiers and police near the rebel areas of the upper Kodori Gorge.
But Georgian officials denied intending to attack Abkhazia, which broke away from Georgia in the 1990s.
Interior ministry spokesman Shota Utiashvili told the news agency AFP that "there has been no increase in forces from the Georgian side, nothing at all. The Russian statement is simply not true."
He also objected to Moscow's announcement of an increase in peacekeeping forces in Abkhazia and South Ossetia, in response to what Russia sees as Georgia's aggressive moves.
Mr Utiashvili said: "This is not acceptable to us... they cannot increase the number any further."
"It is the Russians who are taking provocative actions, not Georgia. Deploying additional troops is certainly a very provocative move," he added.
Georgia's president has vowed to reunite the country
Russia has kept a peacekeeping force in Abkhazia and South Ossetia under an agreement made following the wars of the 1990s, when they broke away from Tbilisi and formed links with Moscow.
There are around 2,000 Russians posted in Abkhazia, and about 1,000 in South Ossetia.
Tensions between Russia and Georgia have flared up recently, despite Russia lifting economic sanctions against Georgia earlier this month.
Last week Russian authorities insisted Abkhaz rebels had shot down an unmanned Georgian spy plane - after Georgia accused a Russian plane of shooting down the drone.
And on Tuesday Georgia said it was blocking Russia's entry to the World Trade Organisation.
Many in Abkhazia believe that Kosovo's announcement of independence from Serbia in February provides a precedent for it to be recognised as an individual state.
Although it has its own flag and postage stamps, it is not internationally recognised.
Our correspondent in the area says that with this latest statement the Russian government has pushed the already bellicose rhetoric between the two countries to a new level.