Doku Umarov released a video in June, lifting a moratorium on attacks inside Russia and encouraging rebels to use "maximum force" to try to prevent the 2014 Games.
In the video, Umarov said the moratorium, put in place last year after attacks against infrastructure in Moscow were followed by massive protests against the Kremlin, was mistaken by President Vladimir Putin as weakness.
"Today we must show those who live in the Kremlin... that our kindness is not weakness," Umarov said. "They plan to hold the Olympics on the bones of our ancestors, the bones of many, many dead Muslims buried in our land by the Black Sea."
"We as mujahideen are required not to allow that, using any methods that Allah allows us," he said.
Sochi is relatively close -- just 250 miles -- from Chechnya and Dagestan, where significant populations of Muslims live under Russian authority and where a low-intensity rebellion has continued for two decades.
Security is considered a major concern ahead of the Sochi games, and though Russian state media did not report on Umarov's announcement, it did say the anti-terrorist committee was "paying special attention to questions of preparation for major sporting events of a global scale."