<sod >ÃÂÃÂ  Speaking to reporters on Tuesday - hours before US Secretary of State Rex Tillerson is due to arrive in Moscow - Mr Putin said he would appeal to the UN to investigate last week's alleged chemical attack in Syria.< eod>< sod > Speaking to reporters on Tuesday - hours before US Secretary of State Rex Tillerson is due to arrive in Moscow - Mr Putin said he would appeal to the Organisation for the Prohibition of Chemical Weapons to investigate the recent alleged chemical attack in Syria.< eod>