Donald Trump will announce his latest round of tariffs at the White House on Wednesday afternoon, threatening to unleash a global trade war on what he has dubbed “liberation day”.

Trump has rattled global stock markets, alarmed corporate executives and economists, and triggered heated rows with the US’s largest trading partners by announcing and delaying plans to impose tariffs on foreign imports several times since taking office.

No details of Wednesday’s plans have been made available ahead of the announcement. The president is set to speak at 4pm ET. White House officials said that the implementation of the most sweeping rewrite of US trade policy would be immediate.

Trump has made clear a few goals he wants to accomplish through his tariffs: bring manufacturing back to the US, respond to unfair trade policies from other countries, increase tax revenue and incentivize crackdowns on migration and drug trafficking.