The Bush administration welcomed the confirmation of the death penalty against Saddam Hussein, reopening the divide with the European Union and the United Nations, which are opposed to execution.
Human rights groups, including Amnesty International and Human Rights Watch, said Saddam should not be hanged for crimes against humanity because his trial had been flawed and was marred by political interference by the Iraqi government.
A spokeswoman for Amnesty said: "We are against the death penalty as a matter of principle but particularly in this case because it comes after a flawed trial."
Richard Dicker, director of the International Justice Programme at Human Rights Watch, said: "Imposing the death penalty, indefensible in any case, is especially wrong after such unfair proceedings. That a judicial decision was first announced by Iraq's National Security Adviser underlines the political interference that marred Saddam Hussein's trial."
Iraq's US-appointed interim government reinstated the death penalty in August 2004, causing friction with its coalition partner, Britain. The former top British representative in Iraq, Sir Jeremy Greenstock, said the UK would not participate in a tribunal or legal process that could lead to execution.
A Foreign Office spokesman said yesterday that while the execution of Saddam was "a matter for the Iraqis", Britain remained opposed to the death penalty, and had made representations to the government on that score.
The outgoing UN secretary general, Kofi Annan, has expressed opposition to imposing the death penalty on Saddam on principle.
But the deputy White House press secretary, Scott Stanzel, struck a different note. "Today marks an important milestone in the Iraqi people's efforts to replace the rule of a tyrant with the rule of law," he told reporters aboard Air Force One. "Saddam Hussein has received due process and legal rights that he denied the Iraqi people for so long."