The Taliban's reclusive leader said in a Muslim holiday message Saturday that the U.S. and NATO should study Afghanistan's long history of war, in a pointed reminder that foreign forces have had limited military success in the country.

The message from Mullah Omar comes less than a month before the eighth anniversary of the U.S.-led invasion of Afghanistan to oust the Taliban for hosting Al Qaeda leader Usama bin Laden.

This year has been the deadliest of the conflict for U.S. and NATO troops, and political support at home for the war is declining. Taliban attacks have spiked around Afghanistan in the last three years, and the militants now control wide swaths of territory.