WASHINGTON—The Trump administration said it is considering sweeping new limits on imports of steel and aluminum as the next phase of its “America First” economic policies, playing down warnings from economists and allies about the risks of higher prices and trade wars.

“Imports threaten to impair our national security,” Commerce Secretary Wilbur Ross told reporters Friday as he released reports detailing options that he has presented to President Donald Trump to shield U.S. industries from foreign competition.

The options would hit trading partners differently, with varying combinations of quotas and tariffs—some higher than 50%. But all had the same broad goal of cutting imports significantly from current levels in the hopes of boosting domestic production in the two hard-hit sectors.

The reports are just recommendations to Mr. Trump, who has until April to decide which options, if any, to choose, or whether to reject greater protection. Mr. Trump ordered the studies in April and has a year by law to act.

Some kind of action seems likely, as Mr. Trump made stricter limits on metals imports limits a centerpiece of his 2016 presidential campaign and, as president, has repeatedly vowed to fulfill that pledge.