Donald Trump has signed an executive order withdrawing from the Trans-Pacific Partnership trade deal.
The president's decision to quit the decade-long project appears to have scuppered the hopes of many nations for a new, ground-breaking free trade deal across the Pacific.
The Trans-Pacific Partnership is a proposed agreement among 12 Pacific Rim countries aimed at deepening economic ties.
It is designed to cut tariffs while simultaneously creating trade to boost growth.
The TPP could have created a new single market - roughly 40% of the world economy - similar to that in the European Union.
Critics claim that free-trade agreements such as TPP contribute to income inequality in high-wage countries by promoting cheaper goods from low-wage nations.
Trump previously announced that he would withdraw the US from the TPP deal on his first day as president.
The billionaire, who promises to bring back jobs to the US, has previously described it as "a potential disaster for our country".
Critics of the deal also argue income gains would go to those already earning high wages.
The Republican has announced the US will instead create "bilateral trade deals that bring jobs and industry back onto American shores".