Russian co-chair of the OSCE Minsk Group Igor Khovayev did not accept the invitation from the US side to discuss Karabakh. 

“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,” the US State Department’s Bureau of European and Eurasian Affairs wrote on Twitter.