President Donald Trump opened another chapter in his trade war with China, ordering his top trade negotiator to pressure the World Trade Organization to crack down on countries the U.S. doesn’t think should be considered developing nations.

Trump singled out China in a memo to U.S. Trade Representative Robert Lighthizer, saying that “the United States has never accepted China’s claim to developing-country status, and virtually every current economic indicator belies China’s claim.”

The president called the WTO “broken” in a tweet that followed release of the memo.

The WTO is BROKEN when the world’s RICHEST countries claim to be developing countries to avoid WTO rules and get special treatment. NO more!!! Today I directed the U.S. Trade Representative to take action so that countries stop CHEATING the system at the expense of the USA! — Donald J. Trump (@realDonaldTrump) July 26, 2019

He gave Lighthizer 90 days to determine whether there’s been “substantial progress” toward limiting the number of countries considered developing nations. The U.S. may act unilaterally if not, Trump said.

“Although economic tides have risen worldwide since the WTO’s inception in 1995, the WTO continues to rest on an outdated dichotomy between developed and developing countries that has allowed some WTO Members to gain unfair advantages in the international trade arena,” Trump wrote in the memo. “Nearly two-thirds of WTO members have been able to avail themselves of special treatment and to take on weaker commitments under the WTO framework by designating themselves as developing countries.”

Seven of the world’s 10 wealthiest economies, Trump said, claim developing-nation status -- Brunei, Hong Kong, Kuwait, Macau, Qatar, Singapore and the United Arab Emirates. So do Mexico, South Korea and Turkey, who are all members of the Group of 20 and the Organization for Economic Cooperation and Development, Trump said.