The UN on Monday concluded in a report that a Russian fighter jet shot down an unmanned Georgian spy plane last month, boosting Tbilisi's claims of Russian military interference on its territory.
The report, posted on the UN website, said evidence gathered by UN monitors "leads to the conclusion that the aircraft belonged to the Russian air force" and that the downing was "fundamentally inconsistent" with ceasefire accords.
Russia's defence ministry rejected the findings, with spokesman Alexander Drobyshevsky telling AFP: "We deny this report. Our planes did not violate anyone's airspace and therefore could not have fired a shot."
The incident is one of the most serious in the region since the end of a military conflict in 1993 between Georgian troops and Moscow-backed separatist rebels in the Georgian breakaway province of Abkhazia.
Georgian President Mikheil Saakashvili said the report vindicated Tbilisi's claims that the Russian military has been violating its sovereignty.
"Georgia today is in a very difficult situation because foreign armed forces have entered its territory," he said in televised remarks.
"The UN has released a report in which Russia is directly accused of aggression against Georgia.... For the first time, the UN has directly, unequivocally pointed the finger at Russia."
Russia, which backs the Abkhaz rebels in the lush Black Sea province, has denied violating Georgian airspace and says that Abkhaz forces shot down the Georgian drone on April 20 -- a claim supported by Abkhaz officials.