ArmInfo.The Russian Co-Chair did not accept the invitation to discuss the future of  Nagorno-Karabakh, the Bureau of European and Eurasian Affairs, U.S. Department of State, reports. 

"The U.S. OSCE Minsk Group Co-Chair spoke with her counterparts today  to discuss the future of Nagorno-Karabakh. It's unfortunate the  Russian Co-Chair did not accept the invitation.  We look forward to  the Minsk Group's continuing work," a Twitter message reads.