The former president spoke at the Detroit Economic Club, shortly after his Democratic opponent, vice president Kamala Harris, virtually attended a briefing in the White House Situation Room about emergency efforts in Hurricane Milton’s wake.
She is scheduled to attend a Univision town hall event in Las Vegas and an evening rally in Phoenix as she remains in close contact with federal authorities about the storm.
Mr Trump offered empathetic messages to people affected by hurricanes Helene and Milton, which came ashore on Wednesday night.
He also suggested the federal response had been lacking, particularly in North Carolina, where he alleged the government after Helene had “not done what you’re supposed to be doing”.
“They’ve let those people suffer unjustly,” said Mr Trump, who has for several days promoted falsehoods about the response of President Joe Biden and emergency management officials.
President Joe Biden has repeatedly condemned Mr Trump for spreading misinformation about federal assistance available to victims, including falsely claiming that such assistance is capped at 750 dollars (£575). In reality, that is just for immediate needs, the first potential payout rather than the total.
“That 750 dollars that they’re talking about, Mr Trump and all those other people know it’s a lie to suggest that’s all they’re going to get,” Mr Biden said on Thursday.
“It’s just bizarre. They got to stop this. They’re being so damn un-American with the way they’re talking about this stuff.”
Asked if he planned to speak with Mr Trump to urge him to stop, Mr Biden said he would not, but followed that with a message delivered directly into TV cameras: “Mr President Trump, former president Trump, get a life, man. Help these people.”
Despite the storm, Mr Trump and Ms Harris are slated to visit key swing states on Thursday, using their travel strategically, trying to increase support with key voting blocs who could decide an election expected to be exceedingly close.
In Michigan, where he is looking to appeal to primarily to blue-collar voters, Mr Trump took a swipe at the city he happened to be campaigning in, suggesting Detroit was “a mess”.
“Our whole country will end up being like Detroit if she’s your president,” he said of Ms Harris. “You’re going to have a mess on your hands.”
He also used his speech to echo core themes from his 2016 campaign, saying some other countries, especially China, are ripping the US off and taking manufacturing business away.
He said powerful companies have “raped” the US and vowed to impose huge tariffs that he said would force other countries to negotiate what they charge on American products.
“They’ve been screwing us for so many years that we’re allowed to get some of that back,” Mr Trump said about charging tariffs from countries.
Ms Harris is out west as she looks to increase support among Hispanic voters, especially men.
Her campaign began a group this week known as Hombres con Harris, which is planning to hold events at Latino-owned small businesses, union halls, barbecues and community events until Election Day.
The Harris campaign has also aimed to reach Hispanic voters who may not be closely following the election by doing things like having Julie Chavez Rodriguez, Ms Harris’s campaign manager, attend the recent boxing match between Canelo Alvarez and Edgar Berlanga in Las Vegas, and holding events at churches and elsewhere to mark Mexican Independence Day in September.
Her campaign also announced last month that it was spending 3 million dollars (£2.3 million) on Spanish-language radio ads and focusing on sport events like baseball and boxing.
Her appearance in Nevada also coincided with a Democratic National Committee effort to put bilingual billboards in Las Vegas and ads promoting the importance of voting in Spanish language newspapers in southern Nevada.
Hispanic voters are about evenly split on whether to trust Ms Harris or Mr Trump to do a better job handling the economy, but they give the former president an edge on handling immigration.
