BAGHDAD (CNN) -- U.S. authorities haven't received a request from Iraq for the release of Ali Hassan al-Majeed, the one-time Saddam Hussein henchman awaiting execution, an American military spokesman said Wednesday.
Ali Hassan al-Majeed listens to evidence at his trial in Baghdad in January 2007.
"We will fulfill our responsibility once that request has been submitted to us," said Brig. Gen. Kevin Bergner, spokesman for the U.S. military.
Al-Majeed, a cousin of Hussein's, is known by the nickname "Chemical Ali" for his role in a chemical weapons attack on Iraqi Kurds in the 1980s.
A court convicted al-Majeed for his part in the crackdown that killed at least 100,000 Kurds, including a 1988 attack with poisonous gas and chemical agents that left 5,000 people dead in the village of Halabja.
The execution approval came from Iraqi President Jalal Talabani, a Kurd, and the two vice presidents -- Tariq al-Hashimi, a Sunni, and Adel Abdul Mahdi, a Shiite, according to a member of Iraq's parliament speaking on condition of anonymity.
Iraqi law requires the three members of the country's presidency council to sign the execution warrant.
A high-ranking official in al-Hashimi's office said Friday that the execution should happen within 30 days.
Bergner also announced Wednesday that the U.S. has released from custody two former Iraqi Health Ministry officials acquitted this week in connection with death squad activities.
Hakim al-Zamili, a former deputy health minister, and Brig. Gen. Hamid al-Shammari, who led the ministry's security forces, were arrested last year on charges of murder, kidnapping and corruption.
A three-judge panel from the Central Criminal Court of Iraq on Monday found the two not guilty. Bergner said they were released after a request from Iraqi authorities.
The men, part of the political movement linked to Shiite cleric Muqtada al-Sadr, were charged with facilitating killings and kidnappings of Sunnis from hospitals.
Also Wednesday, a professor who served in Iraq's government during the 1970s was shot and killed in the northern Iraqi city of Kirkuk, sources said.
Abdulsattar Taha Shareef, 78, was driving to Kirkuk University when he was gunned down, said police, who are treating the killing as an assassination.
Police said Shareef had been a government official under Hussein, and his relatives said he served in a previous Iraqi regime as well.
He fled the country in 1994 when he learned the Hussein regime was planning to assassinate him, relatives said.
Shareef lived in New Zealand for about eight years and then came back to Iraq after Hussein was toppled in 2003.
Meanwhile, an Iraqi official and a state-run Iranian news agency said Wednesday that Iran and the United States would meet on Thursday in Baghdad, but the U.S. denied any such plan.
"The United States government has no plans to have a meeting tomorrow," State Department spokesman Tom Casey said.
"Logistically, it would be impossible to do so," because preparations such as Farsi translators and planning for the meeting haven't been made.
Phil Reeker, counselor for public affairs at the U.S. Embassy in Baghdad, also said there are no talks Thursday and none scheduled at this point.
Iran and the United States have held meetings about security in Iraq three times since last May, and Iraqi delegations have hosted and taken part in those meetings. E-mail to a friend
CNN's Mohammed Tawfeeq contributed to this report.