US Ambassador to Azerbaijan Reno Harnish is concerned over the developments at the contact line between the Armed forces of Azerbaijan and Nagorno Karabakh, Day.az reported. "The repeated breaks of the cease-fire makes worry. At the same time it proves that the conflict is not frozen and it demands a solution," R. Harnish told journalists Wednesday. The Ambassador emphasized that the US follows with attention the developments in the Nagorno Karabakh conflict region. "We understand the importance of not admitting breaks of the cease-fire regime at the front line," he noted.