Four major unions called on Donald Trump on Wednesday to increase American shipbuilding and impose tariffs and other “strong penalties” against China because of its growing dominance in this sphere.

Presidents of United Steelworkers International Brotherhood of Electrical Workers International Brotherhood of Boilermakers and International Association of Machinists and Aerospace Workers claim that China’s actions have hurt American workers and undermined national security.

The letter urged Trump “to impose harsh penalties on vessels built per the plans, policies, and actions of China’s Communist Party, and to adopt a complementary policy that rebuilds America’s shipbuilding capability and workforce.”

The unions submitted a petition under the presidency of Joe Biden last year, asking for a response to China’s shipbuilding in Section 301, 1974 U.S. Trade Act. They hoped to begin a process that would lead to tariffs and other actions.

In the letter, it is noted that China will produce more than 1,000 oceangoing vessels by 2023 while the United States will only make less than 10 ships. The letter also notes that China’s shipbuilding industry has received over $100 billion in government assistance from 2010-2018 so Chinese shipyards made up the majority of orders worldwide last year.

In a separate press release, Brian Bryant, president of the machinists, aerospace, and workers union, stated that he had personally witnessed the devastating effects of China’s predatory action on the domestic shipbuilding industry. “For decades, our shipbuilding industry has been weakened by everything from shipyard closures and layoffs to the atrophying of our domestic industrial base.”

Trump’s top priority is to control the Panama Canal and reset the global trade terms with tariffs. Many of Trump’s concerns are directed toward U.S. Allies like Canada, Mexico, and the European Union. He has also imposed an extra 10% tariff on imports coming from China because it is responsible for the production of the opioid fentanyl.

The White House said that it was considering all options available to counter China’s practices, particularly in the sectors of maritime, logistics, and shipbuilding.

Hugh Hewitt is a conservative radio talk-show host who interviewed Trump in January.

“We don’t build ships anymore,” Trump said. “We want to get that started. And maybe we’ll use allies, also, in terms of building ships. We might have to.”

In an interview with Fox News Channel that aired on Tuesday night, Trump mentioned the decline of American shipbuilding. He said he wanted to see that change.

“We don’t build like we used to.” He said, “Yeah, we used to build a boat a day. Now, to build a vessel is like a huge deal.” “We’re going back on track to bring this country up to speed.”