The U.S. Treasury Department proposed a rule Thursday to crack down on American high-tech investments such as supercomputing and artificial intelligence in China, Russia, North Korea and other "countries of concern."

Collins, locked in a tight race with Democratic challenger Troy Jackson, issued a statement saying she'd spoken with Trump's top trade negotiator, Jamieson Greer, and Commerce Secretary Howard Lutnick "about the toll tariffs are taking on Maine families, businesses, farmers, and growers.''