She claims Mr Farage has appeared on Russian propaganda programmes
Hillary Clinton has slammed Donald Trump for appearing with Nigel Farage, whom she described as "one of Britain's most prominent right-wing leaders".
Speaking in Reno, Nevada, the Democratic presidential candidate said the former UKIP leader, who appeared on stage with the Republican nominee in Mississippi on Wednesday, had "stoked anti-immigrant sentiments" to win June's Brexit referendum.
"Farage has called for a ban on the children of legal immigrants from public schools and health services," she continued, "has said women are quote 'worth less' than men, and supports scrapping laws that prevent employers from discriminating based on race - that's who Trump wants by his side."
"Farage has appeared regularly on Russian propaganda programmes," she added.
"Now he's standing on the same stage as the Republican nominee."
Mr Farage hit back saying that Mrs Clinton was "running scared".
"Her attacks on me are completely baseless," he said. "She sounds rather like Bob Geldof and can't accept Brexit."
"Perhaps Mrs Clinton should spend more time speaking to normal, working people in her country than trying to attack me using dodgy half-quotes."
The main purpose of the White House hopeful's speech was to accuse Mr Trump of "taking hate groups mainstream" with a campaign based on "prejudice and paranoia".
She sought to link her Republican rival with the "alt-right" movement, which opposes multiculturalism.
Mrs Clinton said Mr Trump's "disregard for the values that make our country great is profoundly dangerous".
"This is someone who retweets white supremacists," she added, charging him with "a steady stream of bigotry".
The businessman, who is trailing in the polls three months before election day, said earlier that Mrs Clinton was accusing his supporters "of being racists, which we're not".
He told a rally in Manchester, New Hampshire, it was "the oldest play in the Democratic playbook".
Mr Trump said his rival's speech was a "brazen" bid to distract from questions about her family foundation and private e-mails.
He also accused Mrs Clinton of "a vast criminal enterprise run out of the State Department".
Mr Trump said revelations that scores of donors to the Clinton family foundation met with her as Secretary of State represents "one of the most shocking scandals in American political history".
"It's Watergate all over again," he said.