President Donald Trump has threatened that the United States will pull out of the World Trade Organization if the global trade body does not stop taking advantage of the country, and end its unfair treatment. "We will leave if we have to," he said while addressing workers at Shell Pennsylvania Petrochemicals Complex in Monaco, Pennsylvania. "We know that they have been screwing us for years and it's not going to happen again." As President, Trump has taken a tough line on the WTO, and threatened to withdraw from the world trade body multiple times. According to him, the treaty establishing the body "was the single worst trade deal ever made." Co-founded by the United States in 1995, WTO is an intergovernmental organization to regulate international trade and resolve disputes between the member states. It is feared that Washington's withdrawal from the apex trade body would undermine the cornerstone of international trade system. Trump had earlier complained that the Geneva-based WTO has been treating the U.S. "very badly" for many years, and the country is at a big disadvantage because the body too often rules against it. But Washington has a successful track record of winning disputes mediated by WTO, AFP reported. The Trump administration has effectively paralyzed the work of the WTO's Appellate Body by blocking judicial appointments to the panel that arbitrates disputes. China, the United States' major trade rival, alleges that U.S. policies are threatening the existence of the World Trade Organization, WTO members are engaged in a debate about reforms to the world trade body to ensure that the organization can remain responsive to the challenges of today's economy. At the recent G-20 summit, world leaders called for making basic reforms to the organization. The impasse in the dispute settlement mechanism remains the most pressing issue. The United States has been engaged in long standing disputes with many countries at the World Trade Organization, including China, Japan, India and the European Union. A recent report by the Congressional Research Service said the tariffs imposed by the Trump Administration, combined with retaliatory measures adopted by other countries, are having noticeable effects on trade flows and U.S. firms. According to the WTO, the United States is currently involved in 278 active trade disputes being addressed in its dispute settlement system.