If the World Trade Organization doesn't "shape up," the US president said he "would withdraw from the WTO."

"If they don't shape up, I would withdraw from the WTO," Trump said in an interview with Bloomberg on Thursday. It's not clear what topic under discussion led Trump to make the remark.

However, this isn't the first time Trump has taken aim at the Geneva-based organization.

The multilateral organization must "change their ways," he has said, since Washington has been treated "very badly" by the WTO for a while.

"We're demanding fairness with the World Trade Organization. It's been a disaster for the United States, and we want fairness. We lose court cases. We always had a minority of judges; they gave us fewer judges than other countries had," Trump said in July.

"And we'd lose cases — nobody knew why. I said 'I know why: because you don't have judges from this country.' You have a minority. Three to two, with three being on the other side," he said. "And we started to do much better lately in winning cases."

US Trade Representative Robert Lighthizer said in January it was a "mistake" for the WTO to allow China to enter the organization. Trump and Lighthizer have spearheaded a tit-for-tat trade fight with Beijing by imposing tariffs on billions of dollars worth of Chinese products sold to the US market. China has responded in kind with retaliatory tariffs. Bloomberg reported Thursday that Trump intended to sign off on tariffs on an additional $200 billion worth of Chinese goods next month.