(Reuters) - Russia and Ukraine are coming closer to an understanding on secondary issues at peace talks but there has been limited progress on the key questions, Moscow negotiator Vladimir Medinsky said on Friday, the Interfax news agency reported.

       "Negotiations have been going on all week, from Monday to Friday, in video conference format, and will continue tomorrow," Interfax quoted Medinsky as saying. "On secondary issues, positions are converging. However on the main political issues, we are in fact treading water."

       (Reporting by Reuters; Editing by Conor Humphries)