President George W. Bush called the vote a resounding success.
"There's more distance to travel on the road to democracy, yet Iraqis are proving they are equal to the challenge," Bush said in remarks at the White House 22 months after US-led forces invaded Iraq to oust Saddam Hussein.
"Today the people of Iraq have spoken to the world, and the world is hearing the voice of freedom from the centre of the Middle East," he said. "The Iraqi people themselves made this election a resounding success."
"Terrorists and insurgents will continue to wage their war against democracy, and we will support the Iraqi people in their fight against them," he promised.
Hope for return to self-rule
The United Nations, Middle Eastern and European leaders voiced the hope the polls would usher in a speedy return to self-rule in the war-torn country.
British Prime Minister Tony Blair, Bush's closest ally in Iraq, said the election was "a blow right to the heart of the global terrorism that threatens destruction not just in Iraq but in Britain and virtually every major country around the world".
He said the "force of freedom had been felt throughout the country".
Annan appeals for reconciliation
UN Secretary General Kofi Annan appealed to Iraqis for reconciliation "on all sides" following the poll.
"It will be some days before final results are known, but current indications are that the elections have been successfully carried out. I wish to pay tribute to the courage of the Iraqi people, and to congratulate the Independent Election Commission of Iraq," the UN chief said.
The French government, which was one of the fiercest opponents of the US-led invasion of Iraq, hailed the vote as a "great success for the international community" and called the high voter turnout "good news".
In Iraq's Shiite neighbour Iran, parliamentary deputy Alaeddin Boroujerdi hailed the vote as a "great step for Iraqis towards an independent and popular regime".
Anxiety in Arab nations
But former Iranian president Akbar Hasemi Rafsanjani warned Washington may "rig the results" or stage a coup to prevent Iraq from becoming a country that is "free and independent and that does not stand next to America and Israel".
Arab nations anxiously awaited the results to see if the vote would mark a further step towards democracy, or the start of civil war.
"One eye filled with fear, the other with hope" was the headline of a commentary in the London-based Saudi daily Al-Sharq Al-Awsat, setting the overall mood.