Vice presidential nominees Sarah Palin and Joe Biden have disagreed sharply on the roots and the remedies of the US financial crisis at their crucial running mates' debate.

Republican Palin (44) and Democrat Biden (65) faced off in St. Louis, Missouri for a 90-minute showdown, seeking to land blows on behalf of presidential nominees John McCain and Barack Obama.

"Nice to meet you, can I call you Joe?" Palin said, in a comment picked up by microphones as she walked on stage and shook hands with her adversary, as she faced mounting questions about her qualifications for the job.

Delaware Senator Biden returned the compliment as he answered his first question about the $700-billion Wall Street bailout up for a vote in the House of Representatives on Friday.

"Governor, it's a pleasure to meet you," Biden said.

Early exchanges narrowed in on the financial crisis, and its debilitating impact on the US middle classes.

Palin blamed Democrats for embracing wealth distribution and high tax policies that she said would limit growth. Biden argued that eight years of Republican policies were to blame for the economy's nightmare.

'Hockey mom' persona

The Alaska governor framed herself as the kind of middle-class person that attends kids' soccer games, and again putting forward her "hockey mom" persona, said she had been a reformer as a small town mayor and governor and was an expert on energy.

"I may not answer the question the way you want to hear but I'll talk straight to the American people and let them know my track record also," she said.

Biden avoided all but the most gentle attacks on Palin's answers, concentrating mostly on an attempt to demolish McCain's credibility on the economy.

"It was two Mondays ago that John McCain said at nine in the morning that fundamentals of the economy were strong.

"Later that day John McCain said we had an economic crisis — that doesn't make John McCain a bad guy but it does point out he's out of touch," he said.

Palin chose not to parry a Biden argument that McCain had argued against greater regulation on Wall Street, and contributed to the debt-laden crisis threatening the US economy.

Instead, she argued that Obama had voted in the Senate to raise taxes 94 times, a claim that has been questioned by newspaper reports and independent fact check operations.

She also painted McCain as a "maverick" immune from the kind of Washington logjam politics she framed his long-time Senate colleague Biden as representing.

Millions of viewers

Millions of viewers were expected to tune in to watch the 90-minute debate, to see the two rivals stand at podiums and parry question from PBS public television anchor Gwen Ifill.

Concern mounted about Palin's readiness since she stumbled in several interviews on foreign policy, the economy and the Supreme Court.

She has faced widespread ridicule for some of her answers, including citing Alaska's proximity to Canada and Russia as valid foreign policy experience.

Biden has 35 years experience in the Senate, and while he is known for often being too verbose, he has plenty of high-profile debates under his belt.

McCain on Thursday again defended Palin, telling CNN: "She's very comfortable in her own skin.

"I'm very confident about her credentials and her vision and her strength for America and so I'm very proud of her.

"The fact is she'll do fine tonight. She has experience, talent, leadership. She has great inner strength."

Some political analysts and experts said Palin was facing her most crucial test just 33 days before Americans vote.

"This could be what seals the deal. If she does extremely well or extremely poorly, obviously it will be the debate that people say defines Sarah Palin's candidacy," Washington University history Professor Peter Kastor told AFP.

Palin wowed the Republican convention in early September with her speech, and the devout Christian, pro-life, moose-hunting mother-of-five re-energized the party's conservative base reluctant to embrace McCain.

But her star has been fading amid a string of controversies and her stumbling performances in the few media interviews she has granted.

A record number of journalists have descended on the debate site for the most anticipated vice-presidential showdown since the first one in 1976, with more than 7000 students applying for just 300 tickets handed out in a lottery.

It is only the second time in US history that a woman has taken part in the vice presidential debate, following that between Democrat Geraldine Ferraro and Republican George H.W. Bush in 1984.

AFP