WASHINGTON (Kyodo) -- U.S. President Donald Trump said Friday he plans to roll out tariffs on imported cars around April 2, which could deal a blow to Japanese, German and South Korean automakers.

Trump did not provide details, including which countries may be targeted. "I would have done them on April 1. I'm a little superstitious," he told reporters in the Oval Office. "That costs a lot of money, just that one day, but we're going to do it on April 2, I think."

On Thursday, Trump ordered administration officials to prepare for the implementation of reciprocal tariffs, with his Commerce Secretary nominee Howard Lutnick saying such measures could be imposed as early as April 2.

The levies Trump has proposed would raise the import taxes the United States charges on certain products to match what other countries impose on U.S. goods crossing their borders.

"For many years, the U.S. has been treated unfairly by other countries, both friend and foe," Trump said Thursday as he ordered a probe into trade conditions between the United States and other countries.

"America has helped many countries throughout the years, at great financial cost," he added. "It is now time that these countries remember what we've done for them and treat us fairly."

On Friday, Trump reiterated his view that tariffs will save many U.S. industries and help the country cut its trade deficits.

Touching on Nippon Steel Corp.'s planned but blocked acquisition of United States Steel Corp., the president made it clear again that while he opposes full ownership, he would not mind the major Japanese company taking a minority stake in the struggling American producer.

"U.S. Steel would have been closed, totally closed. We saved it, and now it's going to become, I think, very, very profitable," he said.

On Monday, Trump unveiled 25 percent tariffs on all steel and aluminum imports, due to take effect on March 12.

Since returning to the presidency for a nonconsecutive second term on Jan. 20, he has also imposed an additional 10 percent duty on goods from China. His plans for hefty duties on imports from Canada and Mexico have been put on hold for a 30-day period to allow negotiations with the neighboring countries.

It remains unclear if Trump's proposed auto tariffs will be shaped as sector-based or reciprocal duties.