Iraq's Appeals Court has upheld the death sentence against ousted President Saddam Hussein.
Saddam Hussein must be executed within 30 days, Iraqi law says
The court rejected an appeal by Saddam Hussein's lawyers and confirmed that he would be hanged, court spokesman Raed Juhi told the BBC.
The appeal was launched after an Iraqi court sentenced Saddam Hussein to death on 5 November for the 1982 killings of 148 Shias in the town Dujail.
Under Iraqi law, Saddam Hussein must be executed within 30 days.
"It cannot exceed 30 days. As from tomorrow [Wednesday] the sentence could be carried out at any time," Appeals Court judge Arif Shaheen told a news conference in Baghdad.
He added that there could be no further appeal against the verdict.
The White House called the ruling a milestone in Iraq's efforts "to replace the rule of a tyrant with the rule of law".
But India has urged clemency - expressing concern over any delay to the restoration of peace in Iraq - and the EU has called on Iraq not to carry out the death sentence.
The decision of the Appeals Court must be ratified by Iraqi President Jalal Talabani, but Judge Shaheen said Saddam Hussein's sentence could not be commuted.
Saddam Hussein's defence lawyer Khalil al-Dulaimi told the AFP news agency that the court's verdict "was expected".
"We were not at all surprised, as we are convinced that this has been - 100% - a political trial," he said.
The BBC's Peter Greste in Baghdad says the authorities are keeping the time and place of the execution a closely guarded secret.
He says we might only know if Saddam Hussein is finally dead after the sentence has been carried out.
The former president is currently facing a separate trial in connection with a military campaign against Kurdish communities in the 1980s.
But Iraqi authorities have always said that they will carry out the sentence even if court proceedings are still under way, our correspondent says.
Saddam Hussein was convicted of human rights abuses in relation to the killings of the 148 Shias in Dujail, north of Baghdad, after a failed assassination attempt against the former Iraqi leader in 1982.
Saddam Hussein, former Iraqi president: found guilty and sentenced to death
Barzan Ibrahim al-Tikriti, Saddam Hussein's half-brother: found guilty and sentenced to death
Awad Hamed al-Bandar, Chief Judge of Revolutionary Court: found guilty and sentenced to death
Taha Yasin Ramadan, former Iraqi vice-president: found guilty and sentenced to life in jail
Abdullah Kadhem Ruaid Senior Baath official: found guilty and sentenced to 15 years in jail
Abdullah Rawed Mizher, Senior Baath official: found guilty and sentenced to 15 years in jail
Ali Daeem Ali, Senior Baath official: found guilty and sentenced to 15 years in jail
Mohammed Azawi Ali, Baath official: acquitted
Saddam Hussein's half-brother Barzan al-Tikriti and Iraq's former chief judge Awad Hamed al-Bandar were also sentenced to death.
Former Vice-President Taha Yassin Ramadan was sentenced to life imprisonment and three others received 15-year prison terms.
Another co-defendant, Baath party official Mohammed Azawi Ali, was acquitted.
Saddam Hussein has said the court was illegitimate.
Many critics have dismissed the trial as a form of victors' justice, given the close attention the US had paid to it.
Before the sentencing session began, former US Attorney General Ramsey Clark was ejected from the courtroom after handing the judge a note in which he called the trial a "travesty".
Saddam Hussein's defence team had also accused the government of interfering in the proceedings - a complaint backed by US group Human Rights Watch.
The 5 November verdict sparked celebrations in Baghdad but protests in Saddam Hussein's hometown of Tikrit.