Democratic presidential nominee Hillary Clinton has hit back at Donald Trump, accusing him of racial resentment to minorities and bidding for the support of hate groups.

Less than 24 hours prior, the Republican nominee labelled her a bigot.

“This is what I want to make clear today: A man with a long history of racial discrimination, who traffics in dark conspiracy theories drawn from the pages of supermarket tabloids and the far, dark reaches of the internet, should never run our government or command our military,” she said in a speech on Thursday in Reno, Nevada.

“Donald Trump has built his campaign on prejudice and paranoia.”

“He’s taking hate groups mainstream and helping a radical fringe take over one of America’s two major political parties.

“His disregard for the values that make our country great is profoundly dangerous.”

In Mrs Clinton’s view, the business tycoon has done little to deter hate groups seeing him as an ally, even signalling an alignment with them.

She tweeted a video on Thursday showing Ku Klux Klan members and other white supremacists praising Mr Trump, and an interview of the billionaire not immediately rejecting the support of KKK members.

Why do so many Ku Klux Klan members support Trump?

"A lot of what he believes, we believe in." https://t.co/AqB3DLKL9f

— Hillary Clinton (@HillaryClinton) August 25, 2016

Mr Trump has polled poorly with minorities but lately has tried to broaden his appeal to them, hinting at a softening of his hard-line position on immigration.

In an appearance in Jackson, Mississippi, on Wednesday he had called Clinton a “bigot” who would do nothing to help blacks.

“We’ve always had great relationships with the African American community and I’ve made it such a focal point,” Trump said on Thursday before a meeting at his New York headquarters with black and Hispanic Republicans.

“They have really been let down by Hillary Clinton and the Democrats.”

Mr Trump has been heavily criticised by minorities for his proposals on immigration, which include deporting millions of undocumented foreigners, building a wall along the Mexican border, and suspending Muslim immigration to shore up national security.

Trump would ban every Muslim around the world—1.5 billion men, women, and children—from entering the U.S. just because of their religion.

— Hillary Clinton (@HillaryClinton) August 25, 2016

When Trump was getting his start in business, he was sued by the Justice Dept. for refusing to rent apartments to black and Latino tenants.

— Hillary Clinton (@HillaryClinton) August 25, 2016

But recently he has suggested he could soften those positions.

In comments broadcast on Fox News on Wednesday night, Trump said he would be willing to work with immigrants who have abided by US laws while living in the country, backing away from his insistence during the primaries that he would try to deport all 11 million undocumented immigrants.

He said on Thursday he would deliver an immigration speech detailing his updated positions at a later date, after cancelling previous plans to address the issue.

— with AAP