"Under the decree recognizing independence of both republics, which I have signed, our country will help Abkhazia and South Ossetia to ensure their security and if they are attacked we will certainly offer them appropriate support," Medvedev told CNN.
Russia's president signed decrees earlier on Tuesday recognizing Georgia's breakaway South Ossetia and Abkhazia as independent states and called on other countries to follow suit.
The president said that recognizing the independence of Abkhazia and South Ossetia was in line with international law, adding that during the independence debate in Kosovo, Russia's western partners said Kosovo was a special case.
"Each case of recognizing independence is a special case," he said, "A special case in Kosovo, a special case in Abkhazia and South Ossetia."
Abkhazia and South Ossetia broke away from Georgia following the collapse of the Soviet Union in the early 1990s. Georgia has long sought to bring the breakaway regions back under its control, while accusing Russia of trying to annex the republics.
"Until recently we tried to help restore [Georgia's] state unity, but the last nail was driven in following [Georgia's] decision to attack," Medvedev said.
He also said that Russia, while recognizing the independence of S. Ossetia and Abkhazia, had no intention of interfering in other conflicts on the post-Soviet territory.
"As to our involvement in other conflicts, we naturally are not going to do this," he said.
"However, Russia is a state which has to ensure its interests along the entire length of its border, this is absolutely clear," he added.
The move to recognize the rebel republics will further worsen Russia's relations with Western powers, already strained over what they called Moscow's disproportionate response to Georgia's military offensive on South Ossetia.
The United States and the EU have already condemned Russia's decision as "unacceptable and regrettable."
