The Organization for Security and Cooperation in Europe (OSCE) election observations take place when they are requested by the state concerned, OSCE spokesperson Cathie Burton said on Saturday.

"OSCE and ODIHR [the OSCE Office for Democratic Institutions and Human Rights] election observations take place when requested by state concerned, in this case Ukraine. No observation of Crimea referendum," she wrote on her Twitter page.

Burton said that OSCE representatives are fulfilling other tasks in Ukraine.

"Don't get confused! OSCE military observers' are in north and south of Ukraine now. This is not the OSCE and ODIHR election observation [in Crimea]!" she said.