It is impossible to exclude legitimate and legal Syrian leader Bashar Assad from the crisis settlement in the war-torn country, Kremlin spokesman Dmitry Peskov said Thursday. Syria has been mired in a civil war since 2011 as government forces loyal to Assad fight several opposition and radical Islamist militant groups, including the Nusra Front and Islamic State (ISIS). Since the beginning of the Syria civil war, the United States and some of its allies have supported the moderate Syrian opposition while calling for Assad's resignation, while Russia recognized Assad as the only legitimate Syrian authority.