Two days of talks between Armenia and Azerbaijan over the disputed territory of Nagorno-Karabakh have ended without agreement, the US says.
France hosted the high-profile talks between Armenia's Robert Kocharyan and Azerbaijan's Ilham Aliyev.
Nagorno-Karabakh is legally part of Azerbaijan but has been controlled by Armenians since a war of 1988 to 1994.
Correspondents say hopes had been building that a solution would be agreed at last at the talks.
The next step
"There was no agreement," US mediator Steven Mann said after the talks at Rambouillet, near Paris, ended, the Associated Press news agency reports.
What next for Ilham Aliyev (left) and Robert Kocharyan?
"We will assess the outcome of Rambouillet and see where we go from here."
It is not clear what, if any, progress was made at the talks.
The talks at Rambouillet chateau followed mediation by France, the United States and Russia.
More than 25,000 people died in the Nagorno-Karabakh conflict, which also displaced hundreds of thousands of people.
French President Jacques Chirac held separate talks with the Armenian and Azeri leaders before they met face-to-face on Friday.
The two sides have described any future agreement as "packaged and phased", suggesting that an international peacekeeping force would be required, the BBC's regional analyst Steven Eke reports.
Other key issues between the two sides are:
- The removal of Armenian occupying forces from the Azeri territory around Karabakh
- The holding of a referendum by the territory's population, as a matter of self-determination.
The separatist Karabakh administration has said it will not accept any deal reached without its direct participation.
The scope for compromise is severely limited by public opinion in both countries, which firmly opposes any concessions, Steven Eke reports.
Nagorno-Karabakh plays a key role in the cultural self-identification of both Armenians and Azeris, who dispute both its history and modern-day status, he adds.
Nevertheless, a senior US State Department official said on Thursday the Rambouillet talks amounted to "the most important meeting in at least five years regarding this conflict".