Key Points

"We are going to be imposing a 25 per cent increase. We're going to bring it from 25 per cent to 50 per cent -- the tariffs on steel into the United States of America -- which will even further secure the steel industry in the United States," Trump said on X social media platform.

He later posted on social media that the higher tariff rate would take effect on June 4, reports Yonhap news agency.

"It is my great honour to raise the Tariffs on steel and aluminum from 25% to 50%, effective Wednesday, June 4th. Our steel and aluminum industries are coming back like never before. This will be yet another BIG jolt of great news for our wonderful steel and aluminum workers. MAKE AMERICA GREAT AGAIN!" Trump wrote on his Truth Social platform.

The planned rate hike is the latest in his trade policies that focus on tariff hikes, and came days after a trade court ruled his sweeping reciprocal tariffs illegal, which was later blocked by an appeals court to leave the tariffs temporarily alive.

The 25-percent tariffs on most steel imported to the U.S. went into effect in March as part of the Trump administration's broader tariff scheme aimed at reducing America's trade deficits and bolstering local manufacturing.

Data showed earlier Seoul's U.S.-bound exports of steel products declined nearly 19 percent from a year earlier in March.

Outbound shipments of steel products to the U.S. came to US$340 million in March, down 18.9 percent from the same month last year.

It is difficult to assess the impact of U.S. tariffs on Seoul's steel exports as transactions are usually made months ahead, but there may still have been some influence.

Korean steelmakers have been devising response measures to the U.S. tariffs, with some companies planning to increase their production in the U.S.

Hyundai Steel Co. plans to invest $5.8 billion to construct an electric arc furnace-based steel mill in Louisiana by 2029, its first overseas production facility.

- IANS