US Forces on Monday refused to hand three former high-ranking members of Saddam Hussain's government over to the Iraqi government so they could be hanged.

Iraqi Prime Minister Nuri Al Maliki said that the US was trying to thwart his government’s attempts to execute Ali Hassan Al Majeed, widely known as "Chemical Ali", former Defence Minister Sultan Hashem, and a former army commander, Hussain Rashid Muhammad.

The three were convicted of genocide for their roles in a campaign against Iraq's Kurds in 1988 in which tens of thousands of people were killed. Under Iraq's constitution their sentences should have been carried out within 30 days.

Al Maliki is demanding they be handed over so Iraqi justice can take its course, however, the US military said it would continue to keep the men in its custody until the government resolved an internal dispute over the legal and procedural requirements for carrying out the death sentences.

"The Coalition Forces are not refusing to relinquish custody. We are waiting for the GOI (government of Iraq) to come to consensus as to what their law requires before preparing a physical transfer," said Colonel Steve Boylan, spokesman for the US military commander in Iraq, General David Petraeus.

"Changes in Iraqi law subsequent to earlier executions have led to disagreement within the GOI as to what the applicable requirements now are," Boylan said.