"We can, we must and we will win the war on terror," Kerry told hundreds of cheering supporters who greeted him at Nashville International Airport before he speaks on Wednesday to the American Legion -- the largest US veterans' group.

"The way to win the war on terror is to fight a smarter, more effective war on terror," Kerry said. "That begins by electing a president to bring other nations to our side to share the responsibilities."

Republicans have made the war on terror a centerpiece of Bush's re-election drive. But Bush's bid to convince Americans they should not change presidents in the middle of a war was not helped by an interview Monday with NBC's "Today" show, when he was asked if the war on terrorism would ever be won.

"I don't think you can win it," Bush replied. "But I think you can create conditions so that those who use terror as a tool are less acceptable in parts of the world."

On Tuesday, Bush sought to explain his earlier remarks by saying the war was not a conventional one but that the United States would win.

As he prepared to address the Republican Party convention in New York on Thursday, Bush found himself forced to adjust his message in a central issue for his re-election campaign.

"We meet today in a time of war for our country, a war we did not start, but one that we will win," Bush told the American Legion, the nation's largest veterans group.

"It's a different type of war. We may never sit down at a peace table, but make no mistake about it, we are winning and we will win," he said in a speech which repeated this refrain four times.

Bush's response to the Sept. 11, 2001 attacks and his ability to win the war on terror are central to his appeal to Americans for their vote. The Republican president has consistently performed better than his Democratic rival John Kerry when voters are asked about who they most trust to keep America safe from another attack.