US co-chair of the OSCE Minsk Group James Warlick has called escalation in Nagorno-Karabakh unacceptable, the diplomat tweeted Sept. 4.
Earlier, Warlick stressed the need to continue the work on the peaceful settlement of Karabakh conflict.
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.