SOCHI, Russia (Combined Sources)-Presidents of Armenia and Azerbaijan agreed on a preamble to the so-called "Madrid Principles" for the resolution of the Karabakh conflict, which calls for the imperative participation of the latter in the talks and sets nations' right to self-determination as a priority for conflict resolution, said sources with knowledge of the document, reported news.am.

The announcement of the agreement was made by Russian Foreign Minister Sergei Lavrov after Armenian President Serzh Sargsyan and his Russian and Azeri counterparts Dmitry Medvedev and Ilham Aliyev met in a ski resort near the Black Sea city of Sochi.

The meeting, which began with the participation of the three foreign ministers, continued with the three presidents meeting in private. None of the three presidents made public statements after more than two hours of negotiations, reported Radio Free Europe/Radio Liberty.

"The conversation was useful," Lavrov told journalists. "The participants discussed the concrete proposals that were presented by the co-chairs. There is a common understanding - and everybody confirmed that - on the document's preamble."

"Today the main result was that although some parts of the document are not agreed on by the parties, the parties will prepare their own concrete ideas and formulations that would be added to the text. We are confident that this will help the co-chairs in their further work," he said.

Lavrov refused to elaborate on the understandings and remaining sticking points. "This is a subject of negotiations between the parties," he explained. Aliyev and Sargsyan were due to hold more talks in the presence of the French, Russian and US Minsk Group co-chairs later on Friday.