US President George W Bush has interrupted his summer holiday for the second time this week to publicly defend his war on terror.
Bush was passionate in his speech
The US was engaged in a global war that affected the safety and security of every US citizen, he said in Idaho.
America would not wait to be attacked again - like on 11 September - he said.
Mr Bush rejected calls by anti-war protesters for a withdrawal from Iraq, and vowed that the US would "stay, fight and win the war on terror".
"An immediate withdrawal of our troops in Iraq or the broader Middle East, as some have called for, would only embolden the terrorists and create a staging ground to launch more attacks against America and free nations," he told an audience that included families of servicemen and women serving in Iraq.
"We will complete the work in Afghanistan and Iraq," he said.
Mr Bush said terrorists had converged on Iraq from abroad, but the US would not allow the Middle East to become a safe haven for terrorists from which they could plan attacks on democracies.
The Pentagon has announced that it is sending an extra 1,500 troops to Iraq to support security efforts during upcoming elections.
The troops are expected to be deployed before a referendum on a new constitution due in October and to stay for about four months - including the period after general elections envisaged in December.
"These troops will join 180,000 Iraqi security forces and 138,000 coalition forces in helping set the security conditions for successful elections," the Pentagon announcement said.
The new deployment is not significant strategically, says the BBC's Adam Brookes in Washington.
But it is a sign that US troops are not about to begin withdrawing, our correspondent says.
Signs of splits
Mr Bush's speech, another he gave on Monday and appearances by senior administration officials in recent days have all been aimed at batting away emerging challenges to the way that Mr Bush is managing the war in Iraq, he says.
Opinion polls suggest more than 50% of Americans think Iraq is going badly.
Most also believe some or all US troops should be withdrawn from Iraq, according to the polls.
Meanwhile the US anti-war movement has been reinvigorated by Cindy Sheehan, the mother of a US soldier killed in Iraq.
Ms Sheehan's supporters have been camped outside the president's ranch at Crawford, Texas.
And in a sign of splits emerging within Mr Bush's party, a senior Republican senator, Chuck Hagel, has said publicly that the war in Iraq is starting to look like that in Vietnam.