Hitachi President and CEO Toshiaki Tokunaga said Monday that the major Japanese heavy machinery maker plans to expand its investment in the United States.

Noting that the company invested more than $12 billion in the United States in the five years through 2024, Tokunaga said at a news conference, "We want to spend the same amount or more" by around 2030.

The news conference was held in Maryland, as Hitachi's largest railway vehicle plant in North America that is located in the U.S. state started full-scale operations the same day.

U.S. President Donald Trump has introduced a high tariff policy, aiming to revive his country's manufacturing industry. Hitachi is promoting local procurement worldwide, while the high U.S. tariffs have led companies that have advanced into the United States to face higher costs for importing parts and components.

"I'm worried about the impact of the U.S. tariff policy on the global economy," Tokunaga said, voicing concern over the possibility of Hitachi's clients curbing investments in the digital and other fields.

The Hitachi factory, built at an investment of about $100 million, will manufacture 20 train cars per month for use in Washington's subway system and other railway services in the United States.

For the first time, the company introduced quadruped robots equipped with the newest digital technology into the plant. Dog-shaped robots detect scratches on train cars during the manufacturing process. The state-of-the-art technology is also used to transport parts at the factory.

Randy Clarke, general manager and CEO of the Washington Metropolitan Area Transit Authority, told media organizations including Jiji Press that at the WMATA, cars supplied from the factory will be tested from the second half of 2027 and fully used from 2028.