The US Commerce Department has recommended that President Donald Trump impose steep curbs on steel and aluminium imports from China and other countries, reports said.

The agency found that "the quantities and circumstances of steel and aluminum imports 'threaten to impair the national security,' as defined by Section 232 (of the Trade Expansion Act of 1962)", said a Xinhua report.

It recommended several options for the president, which include a blanket tariff for all countries, quotas, or high tariffs targeted at specific countries, including China.

The long-awaited unveiling of the department's “Section 232” national security reviews of the two industries contained global tariff options of at least 24 per cent on all steel products from all countries, and at least 7.7 per cent on all aluminium products from all countries, said a Reuters report.

Trump authorised the probes under a 1962 trade law that has not been invoked since 2001. He has until April 11 to announce his decision on steel import curbs and by April 20 to decide on aluminium restrictions, added the report.

However, China’s Commerce Ministry responded by saying China would take necessary steps to protect its interests if the final decision affects China.

The US National Tooling and Machining Association and Precision Metalforming Association issued a joint statement, saying the recommendations would damage downstream industries.

"The recommendations by the Commerce Department to impose steep tariffs on steel would devastate downstream US steel consuming manufacturers who employ 6.5 million Americans, compared to the 80,000 employed by the domestic steel industry," said the statement.