WASHINGTON (AFP) - President George W. Bush took his re-election campaign to the world stage, defending the invasion of Iraq before the UN General Assembly while Democratic challenger John Kerry kept up his attacks on the war.
Six weeks from the November 2 election, Bush told world leaders: "The work ahead is demanding, but these difficulties will not shake our conviction that the future of Afghanistan and Iraq is a future of liberty.
"The proper response to difficulty is not to retreat; it is to prevail."
But Kerry also took up the Iraq campaign saying that Bush "has really got to get out of denial and recognize and be honest with the American people how difficult this is, and frankly, be honest with our allies who've been pushed aside.
"Ninety percent of the casualties and 90 percent of the cost, 200 billion is coming out of the pockets of American taxpayers," Kerry said in an ABC television appearance on "Live with Regis and Kelly."
Bush did not mention the election in his speech, but took up the battle afterward, telling reporters that Kerry's changing stances on Iraq were "hardly credible."
Democratic rival Kerry has made Iraq the centre of his campaign attacks this week. "Invading Iraq has created a crisis of historic proportions and, if we do not change course, there is the prospect of a war with no end in sight," Kerry said Monday.
The Democratic campaign has seized upon the rising US military toll and mounting insurgency chaos to step up its assault on Bush.
A poll released Tuesday indicated Americans are divided on the value of the war. Forty-three percent believe the Iraq war bolstered the fight against terrorism, while 41 percent said the war undermined it, according to a Harris Interactive poll.
In August, 50 percent of Americans said the war had strengthened the fight against terror and 40 did not.
"The almost daily reports of bombings and attacks, kidnappings and continued killing of Americans and Iraqis seem to do little to change public opinion," Harris Interactive said.
"Most adult Americans, it seems, have made up their minds, and neither the recent news from Iraq nor the campaign rhetoric has had much impact on public opinion."
US media widely reported Kerry's most aggressive attack yet on the Republican president's war. But experts have also questioned whether the Kerry plan to accelerate the military transition and ease the US military burden by securing greater foreign aid is realistic.
"Kerry lays out nice suggestions but I have no reason to assume they'd work any better, in the sense that the international community is willing to contribute to stabilising Iraq," said Judith Yaphe, a former CIA expert on Iraq now at the military's National Defense University, quoted by the Washington Post.
While Bush was before the world's media, Kerry has been taking steps to lighten his stuffy image.
On Monday night, Kerry appeared on the "Late Show with David Letterman" on CBS television, to make a dig at Bush's tax cuts, suggesting the Republican should push for "no estate tax for families with at least two US presidents."
To a question about the agreement to hold three Bush-Kerry presidential debates before the election, and a reported dispute about who would stand or sit during the debates, Kerry quipped: "We compromised and George Bush is going to sit on (Vice President) Dick Cheney's lap."