U.S. President Donald Trump speaks at a rally held at the US Steel plant in West Mifflin, Pennsylvania on the 30th (/Courtesy of AFP Yonhap News)

U.S. President Donald Trump announced on the 30th (local time) that he plans to increase the 25% tariff on foreign steel and aluminum products imported into the United States to 50%.

During a speech at a U.S. Steel plant in the outskirts of Pittsburgh, Pennsylvania, Trump said, "This will make the U.S. steel industry even stronger."

Previously, Trump imposed a 25% tariff on foreign steel products in March based on Section 232 of the Trade Expansion Act, and has decided to double this amount.

While Trump only mentioned steel in his speech, he stated in a post on his social media platform, Truth Social, that he would also increase tariffs on aluminum to 50% as well.

He said, "It is a great honor to raise the tariff on steel and aluminum from 25% to 50%," adding, "This will take effect starting Wednesday, June 4." Trump emphasized that there were loopholes under the 25% tariff rate and noted, "There is no way to evade this measure (increasing to 50%)."

As Trump announced plans to increase steel tariffs to 50%, the export situation for the South Korean steel industry, which has already been impacted by the 25% tariff, is expected to worsen. According to the South Korean steel industry and the Korea International Trade Association, the U.S. accounted for about 13% of South Korea's total steel exports last year.

According to U.S. Department of Commerce statistics, the major steel export countries to the U.S. last year were Canada ($7.14 billion, 23%), Mexico ($3.5 billion, 11%), Brazil ($2.99 billion, 9%), South Korea ($2.9 billion, 9%), Germany ($1.9 billion, 6%), and Japan ($1.74 billion, 5%).

The announcement of the "surprise tariff hike" came in connection with Nippon Steel's acquisition and investment in U.S. Steel. Previously, Trump had effectively approved the acquisition, which he had blocked on national security concerns, on the 23rd and announced his visit to U.S. Steel and a campaign speech on that day.

However, Trump only referred to the agreement between the two parties as a "Planned Partnership," and neither company has clearly stated what this expression specifically means, leaving the details of the agreement still unclear.

Starting his speech, Trump stated, "Today we gather to celebrate the 'blockbuster agreement' that will ensure the historic American corporation (U.S. Steel) remains an American company," adding, "U.S. Steel will maintain its headquarters in the great city of Pittsburgh."

He also emphasized that following the announcement of the steel tariff increase plan, "The group making this investment decision will be very pleased. Because this will ensure that no one can steal your industry," and added, "They could get over that barrier at 25%, but they can no longer do so at 50%." Trump also stated, "I asked that group whether they wanted an increase to 40% or 50%, and they chose 50%."

Trump explained his shift from opposition against Nippon Steel's acquisition, a stance previously held by former President Joe Biden, by stating, "They want to do really great things. They really do. And they will invest billions of dollars. And you will have (management) control," adding, "We will all work together, and we will not be in Washington to watch this happen."

He announced that Nippon Steel's investment in the U.S. steel industry amounts to $14 billion (approximately 19.4 trillion won), stating, "This is the largest single investment in history and the biggest investment in U.S. steel history," and added, "Pittsburgh will once again be recognized as the 'Steel City' in the world."

He also added, "Most of the expenditures for this investment will be made within the next 14 months," stating, "This will create and maintain over 100,000 jobs in the U.S., including 100,000 in Pennsylvania." Trump further stated, "There will be no layoffs or outsourcing, and U.S. Steel workers will soon receive a bonus of $5,000 (about 7 million won)."