Taliban leader Mullah Omar on Monday urged U.S. and NATO forces in Afghanistan to withdraw or face a similar defeat to occupying Soviet troops a generation ago.

In a rare message, posted on militant websites and monitored by the U.S.-based SITE intelligence group, Omar offered a bargain to the U.S.-led forces that drove the Taliban from power in 2001 but are now fighting a fierce insurgency by the Islamist militia.

"Reconsider your wrong decision of wrong occupation, and seek a safe exit to withdraw your forces," said the message, which the Taliban said came from Omar.

"If you leave our lands, we can arrange for you a reasonable opportunity for your departure," he said, adding that the Taliban posed no harm to anyone in the world.

If the occupation persisted, "you will be defeated in all parts of the world ... like the former Soviet Union," Omar said.