"We will leave if we have to", Trump said during a campaign rally in Pittsburgh. "They have been screwing us for years, and it's not going to happen any longer".
Trump said the United States does not need the WTO if the organization fails to address loopholes that favor certain nations.
"They view certain countries like China, India, many countries - they've viewed them as growing, they are growing nations. [...] Well, they have grown, and they had tremendous advantages. We are not letting that happen anymore", he said.
Trump has repeatedly reiterated his criticism of the WTO, claiming that the US is disadvantaged as a member of the global bloc. The US president has also repeatedly called the WTO a "catastrophe" and a "disaster" for the US.
Trump recently directed US Trade Representative Robert Lighthizer to secure changes in the group that would prevent developing countries from utilizing regulatory loopholes.
The White House pointed out in a memorandum that China and many other countries continue to style themselves as developing countries “allowing them to enjoy the benefits that come with that status and seek weaker commitments than those made by other WTO members”.
Shortly after issuing the memorandum, Trump said in a statement that the WTO is "broken" when the world's richest countries claim to be developing countries and get special treatment to avoid WTO rules.
The memorandum points out that seven of the ten wealthiest economies in the world - as measured by GDP per capita on a purchasing-power-parity basis - currently claim developing-country status: Brunei, Hong Kong, Kuwait, Macao, Qatar, Singapore, and the United Arab Emirates.
China, the world's second-largest economy, has been identified by the United States as the most significant abuser of WTO regulations. Since joining the WTO, China has insisted that it is a developing country, according to the memorandum.
Discussions about reforming the WTO have been going on for years and the organization's 164 member states are yet to reach a consensus. They are divided into two camps, with one group of states - including Russia - advocating for the organization's further development, and another calling for developing a new format for the bloc.