In a freewheeling speech at a campaign rally in the western state of Montana, US President Donald Trump has cycled through many of his favourite themes but repeatedly returned to vigorous attacks on Democrats.
He again referred to Senator Elizabeth Warren of Massachusetts as "Pocahontas" to ridicule her claims of Native American ancestry.
"I'm going to get one of those little DNA kits and if I'm debating her, we will toss it to her, very gently so it doesn't injure her arm, and we'll say, 'Pocahontas, I'll give you a million dollars if you take the test to show you're an Indian!"'
Warren is among the Democrats considered a potential 2020 candidate.
Trump also went after US Representative Maxine Waters of California, calling her a "low-IQ individual". She has been calling for his impeachment for more than a year.
Trump leaned heavily into the immigration issue as he rallied supporters on Thursday in Montana. He says they have to vote Republican in November if they want to protect their families and communities. Trump also claims that Democrats "couldn't give a damn" about law enforcement.
He also mocked journalists for questioning his readiness for his upcoming summit with Russian President Vladimir Putin.
He vowed that he'll be prepared for the July 16 summit in Finland.
"I've been preparing for this stuff my whole life."
Trump motioned to news media covering the Great Falls rally and said 75 per cent "of those people are downright dishonest".
His barbs against the media came on a day when newsrooms across the US held a moment of silence in remembrance of five Maryland newspaper staffers who were fatally shot last week by a man who authorities say held a grudge against the publication.