US President George W Bush has said he wished the execution of ex-Iraqi leader Saddam Hussein had been more dignified but insisted that justice was done.
Saddam Hussein was taunted as he stood at the gallows
Mr Bush said he expected a "full investigation" of the way the execution had been carried out.
But he said Saddam Hussein had been given justice that "the thousands of people he killed had not".
Saddam Hussein was taunted at the gallows and mobile phone images were taken that appeared on the internet.
Speaking after meeting Germany's Chancellor Angela Merkel in Washington, Mr Bush said: "I wish, obviously that the proceedings had gone in a more dignified way.
"But my personal reaction is that Saddam Hussein was given a trial that he was unwilling to give the thousands of people he killed."
It was the first time the president had spoken on the controversial execution. The White House had previously been reluctant to comment.
Earlier in the day, Mr Bush spoke via teleconference with Iraqi Prime Minister Nouri Maliki and said he would deliver a speech on a new strategy for Iraq next week.
A top Iraqi official, Sami al-Askari, has told the BBC that no amount of international pressure can stop the execution of two men sentenced to death alongside Saddam Hussein.
Barzan Ibrahim al-Tikriti (right) - Saddam Hussein's half-brother, former head of the intelligence service
Awad al Bandar - former chief judge of Revolutionary Court
Mr Askari said the law did not allow for death sentences to be commuted, even by the president.
No date has been announced for the execution of Saddam Hussein's half-brother Barzan Ibrahim al-Tikriti and former chief judge Awad al-Bandar.
The UN has urged the Iraqi government not to execute them.
UN High Commissioner for Human Rights Louise Arbour said she had appealed directly to Iraqi President Jalal Talabani.
But Mr Askari told the BBC's Arabic service: "Nobody can stop the carrying out of court verdicts."
Saddam Hussein, Barzan and Bandar were sentenced to death over the killings of 148 Shias in the 1980s.
Mr Askari also said two guards employed by the ministry of justice - which is responsible for carrying out of verdicts and death sentences - were being questioned about the taunting of Saddam Hussein and the unauthorised mobile phone images that were taken.
Iraqi national security adviser Mowaffaq al-Rubaie has told the BBC that lessons have been learned and future executions will be handled differently.
"We will take care of all the loopholes of what happened during Saddam's execution and we will leave no stone unturned to pursue those who have spoiled the victory of the Iraqi people in executing Saddam Hussein," he said.