A new ceasefire agreement begins today between Armenia and Azerbaijan.
The U.S. helped broker the deal after two previous ceasefire agreements negotiated by Russia fell through quickly.
U.S. Secretary of State Mike Pompeo said Russia and France also took part in the latest talks.
Leaders are expected to meet with the Armenian and Azerbaijani foreign ministers in Geneva on Thursday to begin peace talks.
The conflict is over a disputed region. Hundreds of troops have died over the last few weeks.