The Organization for Security and Cooperation in Europe (OSCE), which is mediating the negotiations, is expected to release a statement later today.
Officials close to the talks told RFE/RL the two presidents will meet again at a date and venue that remain to be determined.
Kocharian and Aliyev began direct discussions on 10 February after meeting separately with French President Jacques Chirac.
In the run-up to the summit, diplomats expressed guarded optimism that progress could be made toward a framework for settling the Karabakh dispute, which has claimed at least 25,000 lives and driven more than a million people from their homes.
(RFE/RL's Armenian and Azerbaijani services)
Click on the image to view an enlarged map of the Nagorno-Karabakh conflict zone
In February 1988, the local assembly in Stepanakert, the local capital of the Azerbaijani region of NAGORNO-KARABAKH, passed a resolution calling for unification of the predominantly ethnic-Armenian region with Armenia. There were reports of violence against local Azeris, followed by attacks against Armenians in the Azerbaijani city of Sumgait. In 1991-92, Azerbaijani forces launched an offensive against separatist forces in Nagorno-Karabakh, but the Armenians counterattacked and by 1993-94 had seized almost all of the region, as well as vast areas around it. About 600,000 Azeris were displaced and as many as 25,000 people were killed before a Russian-brokered cease-fire was imposed in May 1994.
CHRONOLOGY: For an annotated timeline of the fighting around Nagorno-Karabakh in 1988-94 and the long search for a permanent settlement to the conflict, click here.Click on the icon to view images of the Nagorno-Karabakh conflict (Flash required)
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