President Donald Trump has threatened to withdraw the US from the World Trade Organization (WTO), claiming the body treats America unfairly.
"If they don't shape up, I would withdraw from the WTO," Mr Trump said in an interview.
The WTO was established to provide rules for global trade and resolve disputes between countries.
Mr Trump says the body too often rules against the US, although he concedes it has won some recent judgments, reports BBC.
He claimed on Fox News earlier this year that the WTO was set up "to benefit everybody but us", adding: "We lose the lawsuits, almost all of the lawsuits in the WTO."
However, some analysis shows the US wins about 90 per cent when it is the complainant and loses about the same percentage when it is complained against.
Mr Trump's warning about a possible US pull-out from the organisation highlights the conflict between the president's protectionist trade policies and the open trade system that the WTO oversees.
Meanwhile, Washington has recently been blocking the election of new judges to the WTO's dispute settlement system, which could potentially paralyse its ability to issue judgments.
US Trade Representative Robert Lighthizer has also accused the WTO of interfering with US sovereignty.
What's Trump's issue with the WTO?
The US president has been sounding off about unfair trade since even before he became president.
Mr Trump said on Thursday that the 1994 agreement to establish the WTO "was the single worst trade deal ever made".
The US has been embroiled in a tit-for-tat trade battle on several fronts in recent months.
The one creating the most interest is the one with China, as the world's two largest economies wrangle for global influence.
Mr Trump has introduced tariffs on a number of goods imported into the US.
A third round of tariffs on $200 billion (£154b) of Chinese goods could come as soon as a public-comment period concludes next week, according to a Bloomberg report citing various sources.
Asked to confirm this during the Bloomberg interview, President Trump said that it was "not totally wrong".
China has responded to US tariffs by imposing retaliatory taxes on the same value of US products and has filed complaints against the tariffs at the WTO.
China's commerce ministry has said it "clearly suspects" the US of violating WTO rules.
An initial complaint at the WTO was filed by China in July after Mr Trump imposed his first round of tariffs.
The WTO is at the heart of the system of rules for international trade.
It is the forum for sorting disputes between countries about breaches of global trade rules and it is the forum for negotiating new trade liberalisation.