US President George W Bush has set out his strategy to tackle the violence in Iraq, in an attempt to counter American scepticism over the war.
He gave details of coalition attempts to build up the Iraqi security forces and said: "We will not lose our nerve."
And he accused Iran of contributing to the unrest in Iraq by arming militants with improvised explosive devices.
His speech comes ahead of the third anniversary of the US-led invasion of Iraq on 20 March.
Mr Bush admitted the situation in Iraq "is still tense", but said there was also "signs of a hopeful future".
"Iraqis have shown the world they want a future of freedom and peace and they will oppose a violent minority that seeks to take future away from them by tearing their country apart," he said.
The speech at George Washington University was the first of several in the coming weeks detailing aspects of the White House strategy in Iraq.
Rooting out militants
Mr Bush said the US strategy in Iraq had three elements - politics, the economy and security.
Focusing on security in this speech, he detailed how US forces were working with their Iraqi counterparts to build up a strong national police force and army.
As well as training Iraqi forces, they were helping to root out militant sympathisers and encourage greater diversity.
The goal was to have Iraqis control more territory than the coalition by the end of 2006, thus freeing up US and coalition troops to hunt down wanted militants, he said.
"As Iraqis stand up, America and our coalition will stand down," he said, but warned he would be listening to what his commanders on the ground advised rather than sticking to "artificial timetables".
He accused Tehran of providing Shia militants in Iraq with the capability to build deadly improvised explosive devices (IEDs), saying components clearly produced in Iran had been seized.
"Such actions, along with Iran's support for terrorism and its pursuit of nuclear weapons are increasingly isolating Iran and America will continue to rally the world to confront these threats," he said.
Public relations campaign
Mr Bush's speech comes amid great concern in the White House at polls suggesting a growing number of Americans disapprove of his handling of the war, and doubt the prospects for success, says the BBC's Matt Davis in Washington.
Conflict in Iraq continues to overshadow the domestic agenda the president set out in January in a State of the Union address supposed to reinvigorate his faltering second term.
The public relations campaign mirrors a similar series of speeches that began last November, and which briefly helped boost the president's approval ratings - now hovering at around 41%.
But events on the ground in Iraq will continue to be the biggest driver of US public opinion on the war, our correspondent says.