The United States denied on Sunday that it had any hand in the timing of former Iraqi president Saddam Hussein's death sentence and claimed that Iraq's judiciary was operating "independently."

The idea that "somehow we've been scheming and plotting with the Iraqis" is "preposterous," White House spokesman Tony Snow said, cited by U.S. media.

The United States was to hold key Mid-term elections two days after the announcement of the verdict and the Bush administration has been accused of timing the Saddam verdict ahead of the elections in order to boost public opinion of the weakened Republicans.

Iraqis conducted the trial and "the Iraqi judges are the ones who spent all the time poring over the evidence," Snow said, adding that "it's important to give them credit for running their own government."

"The judiciary is operating independently and we need to give them credit for doing their job and doing it in the way they saw fit and proper," Snow said.

Earlier in the day, Saddam and two of his senior aides were sentenced to death by hanging after the Iraqi High Tribunal found them guilty of crimes against humanity over the execution of 148 Shiite villagers of Dujail in a crackdown on the town after a failed assassination attempt against Saddam in 1982.

The United States invaded Iraq and toppled the Saddam Hussein regime in 2003.