Donald Trump has taken the lead in one national US presidential poll that gives him a slender one point advantage on Hillary Clinton.

The ABC/Washington Post poll put Mr Trump on 46%, the first time he has led in the poll since May. Just over a week ago, he had been trailing by 12 percentage points.

Most polls however, both national and state, still show Mrs Clinton ahead - though by a significantly reduced margin.

As the US presidential election enters the final days of campaigning, Mrs Clinton fought back, labelling her Republican rival a "bully" for his criticism of women's looks.

She was introduced on stage by former Miss Universe, Alicia Machado, who has claimed Mr Trump once called her "Miss Piggy" after she gained weight.

She said Mr Trump had been "cruel" and claimed she had spent years "fighting back eating disorders" as a result of his comments.

US President Barack Obama echoed that sentiment at a rally in Columbus, Ohio, where he suggested that sexism is causing men to support Mr Trump over the woman attempting to become the first female president in US history.

"Has she made mistakes?" he asked the enthusiastic crowd. "Of course. So have I. There's nobody in the public arena over the course of 30 years who doesn't make some. She is a fundamentally good and decent person who knows what she's doing."

But he avoided mentioning the biggest threat confronting her candidacy: the decision by FBI director James Comey to renew a probe into her email system.

Meanwhile, Mrs Clinton focused her efforts on a tightening race in Florida, joined by her husband, Bill. At a rally in Sanford, she concentrated on drawing sharp contrasts between herself and her Republican rival on issues including terrorism and national security.

"I know what happened not far from here at the Pulse nightclub in Orlando," she told the crowd at a rally in Sanford, Florida. "I was in New York City on 9/11 as one of the two senators. I will defeat ISIS. I will protect America."

Mr Trump appeared to be energised by the positive polling. He told Democrats in Wisconsin that if they had already cast their ballots for Clinton, they should change them - and that state law allowed them to do so.

At a rally in Zorn Arena, he said that if Mrs Clinton were elected her legal troubles would continue.

"She is likely to be under investigation for many years, probably concluding in a very large-scale criminal trial," he claimed, before urging early voters to shift their allegiances, "with buyer's remorse".

Mr Trump appears to be trying to expand the electoral map of Wisconsin, where he has been trailing Mrs Clinton for months.

Rather than focusing on areas where the polls are closer, such as North Carolina, Florida, Nevada and Ohio, his team seem newly emboldened, banking on a low Democratic turnout.