"In accordance with the principles of international law, which have been approved by the UN, no country, no nation, no government should take action aimed at the violent change of a political regime in any other country,” Medvedev told French media on Monday on the eve of his visit to Paris.
However, he added: "Right now, I don’t want to say who is right, and who is wrong.”
France became the first European country to openly back on November 13 the new Syrian National Coalition, formed November 11, noting that it would also help arm the rebels.
Since then, the European Union, as well as Turkey and a number of Arab League states, also announced it would back the coalition as "the legitimate representative” of the Syrian people.
Various opposition factions have been locked in a protracted civil war with forces loyal to Syrian President Bashar al-Assad in a conflict that has claimed more than 38,000 people, according to the UN, since it began in March 2011.
Russia has staunchly condemned Western support, whether tacit or declared, for anti-Assad forces, arguing that foreign intervention by outside powers in a country’s sovereign affairs contradicts international law.
Moscow, along with Beijing, has vetoed a series of UN Security Council sanctions against the Assad regime.
While Medvedev condemned the violence pursued by both sides, he reiterated that the "Assad regime and [Assad’s] personal fate” was to be decided by the Syrian people alone.