Moscow, March 28 (IANS): Moscow considers Ukraine's upcoming presidential election illegitimate, a senior official said Friday.

"At present, we believe these elections are illegitimate because they don't match the agreement signed between Ukraine's opposition and president Viktor Yanukovych on Feb 21," Andrei Kelin, Russian envoy to the Organisation for Security and Cooperation in Europe (OSCE), said in a televised news briefing in Vienna.

Kelin said that in order to be legitimate, the country's leader must enjoy the support of the general population, Xinhua reported.

"For that, urgent constitutional reform is required, with no delay," the diplomat noted.

Moscow expected the OSCE monitoring mission would protect the Russian-speaking population in Ukraine against extremism and neo-Nazism, Kelin said.

Early presidential election in Ukraine is scheduled for May 25 after President Viktor Yanukovych was ousted by parliament on Feb 22.