YEREVAN, October 1 (RIA Novosti) - The co-chairmen of the Minsk group on the Nagorny Karabakh conflict will begin their tour to south Caucasus on Thursday to prepare a meeting between the Armenian and Azerbaijani presidents.

The Armenian leader Serzh Sarkisyan and his Azerbaijani counterpart Ilham Aliyev are expected to meet in October on the sidelines of the CIS summit in the Moldovan capital Chisinau.

Nagorny Karabakh, a region in Azerbaijan with a largely Armenian population, has been a source of conflict between the former Soviet republics of Armenia and Azerbaijan since the late 1980s. The conflict is mediated by the Minsk Group of the Organization for Security and Cooperation in Europe, comprising the United States, Russia and France.

Yury Merzlyakov of Russia, Bernard Fassier of France and Robert Bradtke of the U.S. will visit the Armenian and Azerbaijani capitals, Yerevan and Baku, respectively. They would also pay a visit to Nagorny Karabakh's largest city, Stepanakert.