The disaster last week at Russia's biggest hydroelectric dam that is feared to have killed 75 shows the country lags very far behind in technology, President Dmitry Medvedev said Monday.

"The only truth here is this. Our country is technologically very far behind," he said on a visit to the Siberian city of Ulan Ude.

"We really are very far behind and if we don't overcome this challenge then all those threats that everyone is talking about will truly become a reality."

Russian investigators have said a technical fault caused the August 17 disaster at the Sayano-Shushenskaya hydroelectric power plant in southern Siberia and have ruled out terrorism as a possible cause.

Medvedev also accused Russia's enemies of writing out apocalyptic scenarios for its future after the tragedy and calling the disaster a "Chernobyl of the 21st century," in reference to the Soviet-era nuclear reactor accident.

"Those who don't like Russia within its existing borders and don't like its role in the world started rubbing their hands," he said.