"I reject power and I will continue to reject it, and I will be leaving power in the coming days," Saleh said in a speech on state television.
Saleh has been clinging to his position while opposition and ruling party representatives cast about for a formula to see through a transition-of-power deal.
"I call on my supporters to persevere and to confront any challenge," Saleh said.
Protests against Saleh's rule have paralyzed Yemen, weakening government control over swathes of the country and fanning fears Al-Qaeda's regional wing may use the upheaval to expand its foothold near shipping routes through the Red Sea.
Saleh has thrice backed out of signing a Gulf-mediated power transition deal. The opposition says the government is holding up negotiations after Saleh's return from Saudi Arabia, where he had gone for treatment after a June assassination attempt.