BAGHDAD, Iraq (CNN) -- The cousin of Saddam Hussein, known by the nickname "Chemical Ali" for his role in a chemical weapons attack on Iraqi Kurds in the 1980s, will be executed, Iraqi officials said Friday. Ali Hassan al-Majeed's execution should happen within 30 days, according to a high-ranking official in the office of Iraqi Vice President Tariq al-Hashimi, a Sunni. The execution was approved by Iraqi President Jalal Talabani, a Kurd, and the two vice presidents, al-Hashimi and Adel Abdul Mahdi, a Shiite, according to a member of parliament speaking on condition of anonymity. Iraqi law requires the three members of the country's presidency council to sign the execution warrant. Al-Majeed will be executed for his role in a crackdown that killed at least 100,000 Iraqi Kurds, including a 1988 attack with poisonous gas and chemical agents that killed 5,000 people in the village of Halabja. Four months ago, a spokesman for the Iraqi government said during a visit to the White House that "Chemical Ali" would be executed "in the coming days." In June, the Iraqi High Tribunal sentenced al-Majeed and two others to death for their parts in the 1980s military offensive against Kurdish villages in northern Iraq known as the Anfal campaign -- Anfal is Arabic for "spoils" of war. "[Al-Majeed] oversaw an eight-phase military campaign in which thousands of Kurdish villagers were gassed," Miranda Sissons of the International Center for Transnational Justice has said. Sissons observed the Iraqi tribunal that convicted al-Majeed. "The survivors who weren't shot or gassed were herded up into prisons and then taken to kinds of concentration camps," she said. The Associated Press reported that the presidency council didn't approve the executions of two other convicted officials in the Anfal campaign -- Sultan Hashem Ahmed and Hussein Rashid.