US President George W. Bush and Democratic rival Senator John Kerry prepared for a security-policy showdown in their first debate this evening.
The 90-minute, nationally televised session on the University of Miami campus starting at 9 p.m. (2 a.m. Irish time) will give voters their first chance to compare the candidates directly. It could play a big role in tipping a White House race that most polls show is close but leaning toward Mr Bush.
Polls indicate as many as one-quarter of American voters could be swayed by the debates, which often provide insights into not only the candidates' views but their demeanor and personalities.
The session will focus on the war in Iraq, where the US death toll now stands at 1,055, and the war on terror.
The Iraq war and counterterrorism policy have dominated the campaign for months, and Mr Kerry promised to confront Mr Bush.
"George Bush is scaring America. He's talking terror every day and people see terrible images of what's happening in the world, and they're real - people being beheaded, the acts of terror in that school in Russia," Mr Kerry said in an interview with ABC's "Good Morning America."
"I know how to fight a more effective war on terror, and by the end of this campaign, America will make that decision, and that's why I'm going to win," Mr Kerry said, adding he was looking forward to the encounter.
Mr Bush, on a morning trip to Stuart, Florida, for a survey of recent hurricane damage, gave a thumbs up and a smile when asked about the debate by a reporter, but did not reply.
Mr Bush is expected to hammer Kerry for shifting his views on the war, while Mr Kerry has condemned Bush for making America less safe with his rush to invade Iraq without international support and his failure to plan adequately for the war's aftermath.