The message was posted by Alfidaa and Ansar websites.
"Soon, a video message by sheikh Abu Yahya al-Libi, may Allah protect him," read the message posted by both website, posted around 1500 GMT on Sunday.
The United States on Tuesday claimed to have killed al-Qaeda's number 2 in a drone attack.
Libi, one of the trusted lieutenant of slain terror head Osama bin Laden is considered as one of the most capable terrorist of the organisation. He has appeared in numerous al-Qaeda videos.