WASHINGTON, March 28 — The US Supreme Court today declined to hear a challenge by steel companies to former President Donald Trump’s 2018 decision to double tariffs on steel imports from Turkey on national security grounds — a policy move defended by President Joe Biden’s administration.

The justices turned away an appeal by steel importers — including Transpacific Steel LLC and the Jordan International Company as well as Turkish steel producer Borusan Mannesmann and its US subsidiary — of a lower court’s ruling against their challenge.

Trump increased what had been a 25 per cent tariff to 50 per cent, which the steel companies have argued exceeded his authority. They had sought repayment from the US government of the US$54 million (RM227 million) they paid collectively in duties.

At issue is a president’s authority under a federal law called the Trade Expansion Act. That law lets a president set tariffs for the purpose of protecting national security.

The challengers pointed to a provision of the law that establishes a window of 90 days for a president to impose a tariff after receiving a report from the US commerce secretary. In 2018, such a report was submitted in January and Trump announced the initial 25 per cent tariff in March, within the 90-day window. But, the challengers said, his decision to increase the tariff to 50 per cent in August 2018 fell outside that window and was unlawful.

Trump lowered the tariff back to 25 per cent in May 2019.

The Biden administration, which took over the case and defended Trump’s actions, had argued that the later decision was legal because the law allows for a president to modify a tariffs decision outside the 90-day period.

The challengers sued in January 2019, leading the US Court of International Trade to rule in their favour the following year. The US Court of Appeals for the Federal Circuit reversed the trade court’s decision in 2021, prompting the companies to appeal to the Supreme Court. — Reuters