MOSCOW (Reuters) - The leaders of Armenia and Azerbaijan agreed at talks with Russian President Vladimir Putin on Friday to work towards demarcating the border between their two countries after a war that killed at least 6,500 people last year.

       Putin brought together Armenia's Nikol Pashinyan and Azerbaijan's Ilham Aliyev for talks in Sochi, 10 days after the deadliest border clashes between the two sides since a ceasefire was signed a year ago.

       A three-way communique said Aliyev and Pashinyan had agreed to work towards setting up a joint commission to define the border, one of the key issues left unresolved when Russia intervened to stop the fighting last year in and around the enclave of Nagorno-Karabakh.

       Azerbaijan emerged as the decisive victor, recapturing territory it had lost in a previous war between 1991 and 1994. But many questions remain unresolved, including the legal status of Nagorno-Karabakh and the Armenians who live there, who numbered up to 150,000 before the war.

       The communique said the leaders discussed unblocking economic and transport links, but there was no mention of the return of prisoners of war.

       Moscow deployed almost 2,000 peacekeepers to the region after the ceasefire, reaffirming its role as policeman and chief power broker in a volatile part of the former Soviet Union where Turkey also wields increasing influence thanks to its close alliance with Azerbaijan.

       (Writing by Mark Trevelyan; Editing by Matthew Lewis)