Even nations that oppose the death penalty, like US ally Australia, called the execution a "heroic" move for the war-torn country.

"I believe there is something quite heroic about a country that is going through the pain and the suffering that Iraq is going through, yet still extends due process to somebody who was a tyrant and brutal suppressor and murderer of his people," Howard said.

"That is the mark of a country that is trying against fearful odds to embrace democracy and it is a country that deserves sympathy and support and not to be abandoned," the prime minister said.

Japan, the other major US ally in the region, said Saddam's execution had been carried out within the rule of law.

"This is a decision made by Iraq's new government on the rule of law," a foreign ministry official said. "We respect it."

Both Australia and Japan contributed forces to the US-led invasion of Iraq in 2003, which led to the ouster of Saddam, and Australia still has about 1,300 troops involved in operations in the area.

Japan ended its historic deployment to Iraq in July -- although its air force still provides flights into the country to assist the United Nations and the US-led coalition.

But not all nations heralded the hanging of Hussein.

China, which opposed the US-led invasion of Iraq, avoided direct comment on the execution, state media reported.

Chinese Foreign Ministry spokesman Qin Gang said merely that Iraq's affairs should be decided by the Iraqi people when asked about Saddam's hanging early on Saturday morning, Xinhua news agency said.

And Pakistan, a key US ally, described the execution as a "sad event" and expressed hope that it would not further exacerbate the security situation in Iraq.

"The execution of former president Saddam Hussein, which can only be described as a sad event, is another poignant reminder of the violence that continues to grip Iraq," the foreign ministry said in a statement.

"We hope that this event would not further exacerbate the security situation," the statement said.

Muslim-majority Malaysia, which currently heads the Organisation of the Islamic Conference, warned the hanging could trigger more violence in Iraq.

"I think there will be repercussions. The only thing is we hope they will be able to contain this. Because the conflict is not going to end. This is not the answer," Foreign Minister Syed Hamid Albar told AFP.

Syed Hamid said there were divisions within the OIC, the world's largest Muslim grouping, on what Saddam's fate should have been.

"There are divided views on it, but on the question of the need for reconciliation to bring the people back together, end violence and bring stability, there is a common feeling," he said.

India, which had warm ties with Saddam's regime, also condemned the execution and worried that it would exacerbate the conflict in Iraq.

"We had already expressed the hope the execution would not be carried out. We are disappointed that it has been," said foreign minister Pranab Mukherjee.

Fears the execution could spark terror attacks anywhere on the globe prompted South Korea to order its overseas embassies to boost security, although its government has yet to comment directly on the execution.

South Korea has around 2,300 troops in Iraq at the US's request, making it the third largest foreign contingent there after the United States and Britain.

In Southeast Asia, Thailand and Singapore both said they believed the execution had been carried out in accordance with Iraqi law, but Cambodia said the execution should not have taken place.

Cambodia is still struggling to begin its own long-delayed trials for atrocities committed in the 1970s by the genocidal Khmer Rouge.

"Democracy has grown very much in Iraq, but in the end the death penalty still exists," information minister Khieu Kanharith told AFP.

"We do not support the death penalty, but we support the process of finding justice for the people," he added.

Vietnam's Foreign Affairs Ministry described the execution as "an internal affair of the Iraqi people".