UNITED NATIONS (CNN) -- The rift between Russia and Western powers over Georgia burst back into full view on the U.N. Security Council when Russia vetoed a resolution that would have extended the U.N. observer mission in Georgia.
The observer force had been in existence since 1993, but Russia claims that the mission was invalidated by last year's conflict over breakaway regions in Georgia.
"The U.N. mission's previous mandate has actually ceased to exist in the wake of Georgia's aggression against South Ossetia last August," said Vitaly Churkin, Russia's U.N. ambassador, who said it was "unacceptable" to extend the mission.
After the veto Monday night, a statement from the office of U.N. Secretary-General Ban Ki-moon said the U.N. would "take all measures required to cease the operations of the United Nations Observer Mission in Georgia effective 16 June."
Ban "will consult with his senior advisors and his special representative on the immediate next steps," the statement said.
Russia and Georgia fought a five-day war last August over the breakaway Georgian provinces of South Ossetia and Abkhazia -- the first time Russia sent troops abroad in anger since the fall of the Soviet Union in 1991. Both sides blame the other for starting the conflict.
Western powers, including the United States, the United Kingdom and France backed the Georgian government in a conflict that rekindled Cold War sentiments.
The European Union launched a probe to determine how the war began that is due to be completed by the end of next month.
The crux of the controversy remains Georgia's territorial integrity. As a result of last year's war, Russia now considers South Ossetia and Abkhazia sovereign nations independent from Georgia. Russia has no international support for that position aside from the nation of Nicaragua.
The Georgian ambassador to the United Nations, Kakha Lomaia, addressed the Security Council following the vote, saying his nation deeply regrets the apparent end of the mission. He called Russia's position "unconstructive."
The statement from Ban's office added, "the Secretary-General regrets that the Security Council has been unable to reach agreement on the basis of a package of practical and realistic proposals he submitted to the Security Council aimed at contributing to a stabilization of the situation on the ground."
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