WASHINGTON (Reuters) – The U.S. Commerce Department has sent President Donald Trump the results of its national security probe into aluminum imports, Trump administration officials said on Sunday, while declining to disclose details.

White House spokeswoman Lindsay Walters confirmed that the findings in the “Section 232” probe were delivered on Friday, just before many government agencies shut down due to the lack of a government funding deal in Congress.

Another administration official said an announcement regarding the submission was expected on Sunday, but that it would look similar to the one that accompanied a Jan. 11 submission on a parallel probe into steel imports.

That announcement did not divulge whether the Commerce Department found that steel imports pose a threat to national security, nor whether it recommended Trump impose broad new tariffs or quotas on imports to protect domestic producers.

Trump has promised he would take action to protect steel and aluminum workers from imports, especially in the face of Chinese overcapacity in both metals.

But the question of whether to order broad tariffs or quotas on steel and aluminum has been the subject of intense debate in the White House, pitting officials who favor more aggressive restrictions against pro-business factions who favor a more cautious approach to avoid a run-up in prices of the metals or disruptions to U.S. allies that produce them.

“We look forward to swift and decisive action by the President on this issue in order to save the American aluminum industry,” Century Aluminum (CENX.O) said in a statement on Sunday night. “American producers need comprehensive relief against excess capacity from all state supported enterprises — not just China — to create a fair playing field.”

Critics say using national security to erect steel and aluminum tariffs could trigger a trade war with China, undermine the global rules-based trading system and hurt America’s friends more than China, as well as damage global growth prospects.