The televised debate between the vice-presidential candidates was lively from the start with Democratic Virginia Senator Tim Kaine focusing on Donald Trump's refusal to reveal his tax records.
"Donald Trump started this campaign in 2014. He said, if I run for president I will absolutely release my taxes. He's broken, he's broken his first promise. Second, he stood on the stage, he stood on the stage last week, and when Hillary said, 'you haven't been paying taxes,' he said, 'that makes me smart.' So it's smart not to pay for our military, it's smart not to pay for veterans, it's smart not to pay for teachers. And I guess all of us who do pay for those things, I guess we're stupid. "
The debate at a university in Farmville, Virginia, came days after a New York Times reported Donald Trump may not have paid federal taxes for 18 years
Republican Indiana Governor Mike Pence defended Mr Trump.
Pence: "His tax return that showed he went through a very difficult time, but he used the tax code just the way it's supposed to be used, and he did it brilliantly."
Kaine: "How do you know that?"
Pence: "Because he's created a business that's worth billions of dollars."
Kaine: "How do you know that?"
Pence: "If with regard to paying taxes, this whole riff about not paying taxes and people saying he didn't pay taxes for years. Donald Trump has created tens of thousands of jobs."
One exchange saw Tim Kaine criticising the Republicans for praising the Russian President Vladimir Putin.
Kaine: "Governor Pence said inarguably, Vladimir Putin is a better leader than President Obama.
Pence: "That is absolutely inaccurate."
Kaine: "And I just think"
Pence: "I said he's been stronger on the world stage"
Kaine: "No, you said leader and I'll just say this governor, if you mistake leadership for dictatorship and you can't tell the difference, a country that's running its economy. If you can't tell the difference, you shouldn't be commander in chief and Donald Trump's sons say that they are, all these business dealings with Russia, those could be disclosed with tax returns but they refuse to do them. Americans need to worry about whether Donald Trump will be watching out for America's bottom line or his own bottom line."
The debate is the only one to feature the vice-presidential contenders and came as Democratic nominee Hillary Clinton edged ahead of Donald Trump in national polls, and in some of the eight battleground states where the election is likely to be decided.
