Details added (first version posted on 14:21)
Baku, Azerbaijan, Dec. 19
Switzerland's Bern is hosting a meeting between Azerbaijan's President Ilham Aliyev and Armenia's President Serzh Sargsyan, said James Warlick, the OSCE Minsk Group's US co-chair, in a tweet Dec. 19.
The two countries' foreign ministers and co-chairs of the OSCE Minsk Group are also in Bern for the presidents' meeting.
The conflict between the two South Caucasus countries began in 1988 when Armenia made territorial claims against Azerbaijan. As a result of the ensuing war, in 1992 Armenian armed forces occupied 20 percent of Azerbaijan, including the Nagorno-Karabakh region and seven surrounding districts.
The two countries signed a ceasefire agreement in 1994. The co-chairs of the OSCE Minsk Group, Russia, France and the US are currently holding peace negotiations.
Armenia has not yet implemented the UN Security Council's four resolutions on the liberation of the Nagorno-Karabakh and the surrounding regions.