In a campaign-style speech at a General Motors test facility in Michigan, Trump also lashed out at Democrats seeking to end Republican control of Congress, calling his political opponents "communists" to cheers from many in the audience.
"Jobs are up, inflation is down, our border is secure. Factories are opening at record levels. Investment is booming. Michigan is thriving. America is winning like never before," Trump said in a speech that also touched on immigration, the Iran war, voting restrictions and transgender issues.
Presidents often speak at auto plants but it is highly unusual for them to turn speeches at factories into campaign rallies. GM declined to comment on the partisan nature of Trump's speech.
The first 18 months of Trump's second term as president have featured a series of policy-driven economic shocks, driven by an immigration crackdown, higher tariffs and a war with Iran that has boosted the price of oil and threatened global supply chains.
Polls show that the high cost of living remains the top issue for American voters heading into the mid-term November elections, including in Michigan, a key swing state.
Trump's attacks on Democrats reflected a theme he has increasingly embraced in recent weeks. With the Iran war exacerbating Americans' economic concerns, he has sought to energise his political base by presenting Democrats as radicals bent on fundamentally transforming the country.
"We're having the single greatest year we've ever had as a country. We're not going to let these people destroy it," he told an audience that included GM CEO Mary Barra.
During the speech, Trump falsely claimed that Democrats seeking office wanted to raise taxes to 80 per cent and abolish the police. He also described the US trade deficit as having declined by 71 per cent, though the actual number in 2025 was a 0.2 per cent decline.
Michigan voters have become more sceptical about Trump's handling of the economy and trade, according to Bernie Porn, president and pollster at Epic MRA. Trump's job approval rating in the US state has fallen to 33 per cent, with 61 per cent disapproving, while most voters say consumers - not foreign countries - are bearing the cost of tariffs.
"He's got a serious problem going into the midterms because people don't believe him and they don't think he's telling the truth," Porn said of the Republican president's problems in Michigan, where Epic MRA is based.
Michigan will be a critical battleground in the fight for control of Congress, with an open Senate seat drawing national attention. The state's Republican and Democratic voters will choose their nominees in an August primary.