President George W. Bush said last he had no regrets about the unpopular war in Iraq despite the "high cost in lives and treasure" and declared that the United States was on track for victory.
Marking the fifth anniversary of the US-led invasion with a touch of the swagger he showed early in the war, Bush said in a speech at the Pentagon, "The successes we are seeing in Iraq are undeniable."
With less than 11 months left in office and his approval ratings near the lows of his presidency, Mr Bush is trying to shore up support for the Iraq campaign, which has damaged US credibility abroad and is sure to define his legacy.
But he faced the challenge of winning back the attention of war-weary Americans more preoccupied with mounting economic troubles and increasingly focused on the race to pick his successor in the November election.
Mr Bush's Democratic critics used the anniversary to press accusations that the Republican president launched the invasion based on faulty intelligence, mismanaged the war and failed to put together an exit strategy.
"Five years into this battle, there is an understandable debate over whether the war was worth fighting, whether the fight is worth winning, and whether we can win it," Bush told an audience of top military officers and Pentagon employees.
"The answers are clear to me: Removing Saddam Hussein from power was the right decision, and this is a fight America can and must win," he said.
Rejecting calls from Democratic presidential candidates Hillary Clinton and Barack Obama for a timetable for early withdrawal, Bush touted security gains from a troop buildup or "surge" he ordered last year. He insisted that "retreat" would embolden al Qaeda and Iran and put the United States at risk.