On Friday, Trump announced the tariff rate on steel and aluminium imports would double to 50%, starting on Wednesday. He said the move would help boost the local steel industry and national supply, while reducing reliance on China. Trump also said that $14bn (£10bn) would be invested in the area's steel production through a partnership between US Steel and Japan's Nippon Steel, though he later told reporters he had yet to see or approve the final deal. The announcement was the latest turn in Trump's rollercoaster approach to tariffs since re-entering office in January. "There will be no layoffs and no outsourcing whatsoever, and every US steelworker will soon receive a well deserved $5,000 bonus," Trump told the crowd, filled with steelworkers, to raucous applause. US steel manufacturing has been declining in recent years, and China, India and Japan have pulled ahead as the world's top producers. Roughly a quarter of all steel used in the US is imported. The announcement comes amid a court battle over the legality of some of Trump's global tariffs, which an appeals court has allowed to continue after the Court of International Trade ordered the administration to halt the taxes. His tariffs on steel and aluminium were untouched by the lawsuit. Last week, Trump had agreed to extend a deadline to negotiate tariffs with the EU by more than a month. In April, he announced a 20% tariff - or import tax - on most EU goods, but later cut this to 10% to allow time for negotiations. Trump expressed frustration with the pace of talks and threatened to raise the tariff rate to an even higher level of 50% as soon as 1 June. But last week he wrote on social media that he was pushing his deadline back to 9 July, after a "very nice" call with Ursula von der Leyen, the European Commission chief.