Russia on Tuesday denied supplying Syria with chemical weapons, one day after US President Barack Obama warned that the Syrian regime would be crossing a "red line" if it chose to use the weapons against the rebels. According to dpa, Colonel Vladimir Mandych, the director of Russia's national chemical weapons monitoring agency, denied that his country had ever sold chemical weapons to Syria. "I would not go so far as to say that the chemical weapons that Syria has are of Soviet or Russian origin. Russia has never provided chemical weapons to Syria," he was quoted as saying by the Interfax news agency. He also said the world must ensure that the weapons are never used. "The world community should take steps to prevent the use of chemical weapons in the 21st century," said Mandych.