"According to the current international law, only the United Nations Security Council can sanction the use of force against a sovereign state," he said. "Any other approaches, means, to justify the use of force against an independent and sovereign state, [are] inadmissible," said Putin, according to a Reuters report.
However, Putin conceded that Russia would not rule out backing a U.N. resolution if solid evidence confirmed that Assad's regime had used chemical weapons against its citizens.
"The use of force is lawful only when in exercise of self-defense in accordance with Article 51 of the United Nations charter and/or when the Security Council approves of such action," said Ban, according to Reuters. "That is a firm principle of the United Nations."