The head of a rebel movement, Doku Umarov, said in the statement on a rebel website that Moscow only wants "to hide the real situation behind lies."
Earlier in the day, Chechnya's Moscow-backed president had proposed a January 1 deadline for separatists to lay down their weapons.
Alu Alkhanov's suggestion came a day after the director of Russia's FSB domestic intelligence service, Nikolai Patrushev, proposed August 1 as the deadline.
Interfax quotes Alkhanov as saying that extending the deadline would give separatists "time to contemplate their decision."
(AP, Interfax, Kavkazcenter)