An international military operation against the Islamic State in Syria cannot be implemented without a mandate from the UN Security Council, which requires Russian support, Belgian Minister of Budget Andre Flahaut said Tuesday. "The military intervention against the ISIS cannot be carried out without a UN mandate and thus also without Russia," Flahaut, former Minister of Defense, wrote in his official Twitter account. On Friday, Russian President Vladimir Putin said Moscow and Washington were interested in creating an international anti-terrorism coalition, but it was too early to discuss the question of Russia getting involved in direct military action against ISIS militants. The United States leads an international coalition of over 60 countries that has been conducting airstrikes against ISIS radicals since 2014. Syria has been engulfed in a civil war for more than four years. Apart from fighting ISIS militants and other jihadist groups, the country's government forces are also battling a so-called moderate opposition.