Russia announced Wednesday it had deployed a missile battery in Georgia's pro-Moscow rebel region of Abkhazia, infuriating its arch foes in Tbilisi some two years after they fought a brief war.

"We have deployed the S-300 system on the territory of Abkhazia," air force commander-in-chief General Alexander Zelin said in a statement.

"Its role will be anti-aircraft defence of the territory of Abkhazia and South Ossetia, in cooperation with the air defence systems of the army."

Georgia insists that Abkhazia and South Ossetia are an integral part of its territory but Russia in 2008 recognised the two regions as independent after its war with Tbilisi.

"The task of these air defence systems is not only to cover the territory of Abkhazia and South Ossetia but to avert violations of state borders in the air," Zelin said in a statement carried by Russian news agencies.

They were also aimed at the "destruction of any flying object penetrating into the covered territories, whatever aim they were flying with," he added.

In Tbilisi, Georgian Deputy Prime Minister and Reintegration Minister Temur Yakobashvili told AFP that Russia's deployment "should be of concern not only for Georgia but also for other regional actors, including NATO."

Georgia's ambition to join NATO has long flustered Russia.

He said the move by Moscow could be linked to its anger over US plans to install missile defence facilities in former Communist bloc East European countries which have become members of NATO.

"This is changing the balance of power in the region," he said.

"It is also a kind of asymmetric answer to the American missile defence deployment in Eastern Europe.... The Russian government is saying 'if you can do it, we can do it'."

In September 2009 US President Barack Obama scrapped an older plan to deploy anti-missile facilities in eastern Europe, which had been strongly backed by his predecessor George W. Bush.

Under the new plan, Washington will replace the land-based facilities in Poland and the Czech Republic with a sea-based system designed to protect against short- and medium-range missiles from Iran.

But Russia has since raised concerns about the revamped US missile defense plans.

Meanwhile, the Obama administration, which has sought to reset ties with Russia that hit a low over the war in Georgia in the waning months of the Bush administration, played down the S-300 deployment.

"I believe it's our understanding that Russia has had S-300 missiles in Abkhazia for the past two years," State Department spokesman Philip Crowley told reporters.

Asked if it's a good thing to have the missiles there, he replied: "No, but it's not news."

Crowley added: "We can't confirm whether they have added to those systems or not ... We will look into that."

Russia at the weekend marked the second anniversary of the outbreak of the war with Georgia, with Russian President Dmitry Medvedev making a surprise visit to Abkhazia Sunday, his first trip since the conflict.

In an embarrassment for Moscow, only Venezuela, Nicaragua and the tiny Pacific island state of Nauru have followed its move to recognise the independence of Abkhazia and South Ossetia.

First manufactured by the Soviet Union in 1978, the S-300 is a surface-to-air missile system capable of tracking and destroying ballistic missiles, cruise missiles, and low-flying aircraft at a range of up to 100-200 kilometres (62-124 miles).

Nicknamed "the favorite" by Russians, the missile is still seen as one of the most powerful anti-aircraft weapons on the market. It can simultaneously track up to 100 targets and engage 12.

Russia signed a contract to sell the systems to Iran several years ago, but has failed to deliver the weapons amid pressure from the West which fears they would be used against any aerial attack on the Islamic republic.

The 2008 war saw Russian forces pour into Georgia after fighting broke out over South Ossetia, prompting the worst post-Cold War crisis between Russia and the West. An EU-brokered ceasefire has held, despite tensions.