"We, the presidents of the OSCE Minsk Group Co-Chair countries -- France, the Russian Federation, and the United States of America -- remain committed to helping the parties to the Nagorno-Karabakh conflict reach a lasting and peaceful settlement," the statement said. "We express our deep regret that, rather than trying to find a solution based upon mutual interests, the parties have continued to seek one-sided advantage in the negotiation process."
Nagorno-Karabakh, a region that became part of the Russian Empire in the 19th century, has been effectively independent since the dissolution of the Soviet Union in 1991. The area was part of Soviet Azerbaijan, and most other countries do not recognize the Nagorno-Karabakh Republic.
About 85 percent of the residents are Armenian, most of them Christian, while Azerbaijan's population is mostly Muslim.
"We reiterate that only a negotiated settlement can lead to peace, stability, and reconciliation, opening opportunities for regional development and cooperation," the joint statement said. "The use of military force that has already created the current situation of confrontation and instability will not resolve the conflict."