President Donald Trump planned to announce Thursday whether he'll impose tariffs or quotas on steel and aluminum imports, a White House official said.

Increased foreign production, especially by China, has driven down prices and hurt American producers, creating a situation the Commerce Department says poses a national security threat.

Trump tweeted Thursday that many U.S industries, including steel and aluminum "have been decimated by decades of unfair trade and bad policy with countries from around the world. We must not let our country, companies and workers be taken advantage of any longer. We want free, fair and SMART TRADE!"

Trump was expected to announce his decision Thursday, said a White House official, who spoke on condition of anonymity to publicly discuss internal deliberations. Industry officials have been invited to the White House, but it remained unclear what Trump intends to announce.

The president has until April 11 to make a decision on steel, and until April 19 to decide about aluminum.

Thursday's planned announcement, on an issue that has been overseen by Commerce Secretary Wilbur Ross and trade adviser Peter Navarro, caught some top White House officials off guard and left several aides scrambling for details, according to a person familiar with the process who spoke on condition of anonymity to describe internal deliberations. Key Senate offices also did not receive advanced warning that Trump was expected to announce a decision ahead of the April deadlines.

Any action to impose tariffs is likely to escalate simmering tensions with China and other U.S. trading partners. Critics of such a move fear that other countries will retaliate or use national security as a pretext to impose trade penalties of their own. They also argue that sanctions on imports will drive up prices and hurt U.S. automakers and other companies that use steel or aluminum.

The Commerce Department is recommending tariffs on all steel and aluminum imports, higher tariffs on imports from specific countries or a quota on imports.

Ross last month offered the president three options:

—tariffs of 24 percent on all steel and 7.7 percent on aluminum imports from all countries.

—tariffs of 53 percent on steel imports from 12 countries, including Brazil, China and Russia, and tariffs of 23.6 percent on aluminum imports from China, Hong Kong, Russia, Venezuela and Vietnam. Under this option, the United States would also impose a quota limiting all other countries to the aluminum and steel they exported to the United States last year.

—a quota on steel and aluminum imports from everywhere, limiting each country to 63 percent of the steel and 86.7 percent of the aluminum they shipped to the U.S. last year.

Trump last year ordered an investigation into whether aluminum and steel imports posed a threat to national defense. Ross said last month that the imports "threaten to impair our national security," noting, for example, that only one U.S. company now produces a high-quality aluminum alloy needed for military aircraft.

Section 232 of the Trade Expansion Act of 1962 gives the president authority to restrict imports and impose unlimited tariffs if a Commerce Department investigation finds a national security threat.