President Trump has announced that he is considering leaving the World Trade Organization. He is upset with the way the organization treats the United States and is demanding change.

According to Bloomberg:

(Bloomberg) — President Donald Trump said he would pull out of the World Trade Organization if it doesn’t treat the U.S. better, continuing his criticism of a cornerstone of the international trading system.

“If they don’t shape up, I would withdraw from the WTO,” Trump said Thursday in an Oval Office interview with Bloomberg News.

A U.S. withdrawal from the WTO potentially would be far more significant for the global economy than even Trump’s growing trade war with China, undermining the post-World War II system that the U.S. helped build.

Trump said last month that the U.S. is at a big disadvantage from being treated “very badly” by the WTO for many years and that the Geneva-based body needs to “change their ways.”

The U.S. Trade Rep Robert Lighthizer also stated that allowing China into the WTO was a big mistake and the new hardline approach to the WTO is needed.