Iraq's presidency has approved the execution of the man known as Chemical Ali, a cousin of former Iraqi leader Saddam Hussein who served as one of his top advisers.

Iraq's President Jalal Talabani and two vice-presidents endorsed last June's death sentence on Ali Hassan al-Majid, a government adviser said Friday.

Al-Majid was sentenced to hang after being convicted of genocide, crimes against humanity and war crimes for ordering army and security services to use chemical weapons against Kurdish civilians during the 1980-88 Iraq war in an offensive said to have killed some 180,000 people.

The sentence must be carried out within 30 days of the decision.

The presidency has not yet decided on the fate of Hussein Rashid Mohammed, an ex-deputy director of operations for the Iraqi armed forces, and former defence minister Sultan Hashim al-Taie, who were also sentenced with Al-Majid.

Saddam was hanged in December 2006. His execution sparked some backlash after video of the hanging was leaked, showing him being taunted moments before his death.

With files from the Associated Press