The death of al-Qaeda leader Abu Musab al-Zarqawi has been welcomed across the Western world and among Iraqi political leaders.
Speaking at the White House President Bush said the death of the Jordanian-born Zarqawi "is a severe blow to al-Qaeda," a victory in the war on terrorism, "and it is an opportunity for Iraq's new government to turn the tide in this struggle."
He said he believed sectarian violence in Iraq would continue.
Mr Bush said US special operations forces confirmed Zarqawi's location based on intelligence from Iraqis and "delivered justice to the most wanted terrorist in Iraq".
Prime Minister Tony Blair speaks during Prime Minister's Questions at the House of Commons.
British Prime Minister Tony Blair described it as an important development in the bid to bring peace to Iraq. "Today's announcement was very good news because a blow against al-Qaeda in Iraq was a blow against al-Qaeda everywhere," Mr Blair's office said in a statement.
Iraqi Prime Minister Nuri al-Maliki warned that anyone who tried to replace Zarqawi would also be killed. "We will continue confronting whoever follows his path," he said. "It is an open war between us."
US ambassador to Iraq Zalmay Khalilzad said Zarqawi's death marks a "great success" but warned that it will not end violence in the country.
Iraqi Foreign Minister Hoshiyar Zebari described today as a "a happy day" for Iraq and the Iraqi people.
"I think what happened today was a decisive blow for terrorist networks and that Iraq will not be a safe haven for any foreign terrorists. But the war against terrorism and the remnants of Saddam's former regime is not over yet."
Nato spokesman James Appathurai said of Zarqawi: "I can I think safely say that he will not be missed."
Israeli Opposition leader Benjamin Netanyahu told Israel radio that "everyone who wants a better world, free of murderous, crazed terrorism needs to welcome the elimination of Zarqawi".