President Donald Trump issued words of warning for the World Trade Organization on Monday, calling on it to start treating the United States “properly” or the U.S. will take action.

Trump made the comments while seated next to Netherlands Prime Minister Mark Rutte, as the two prepared to hold a meeting in the Oval Office.

“WTO’s treated the United States very badly and I hope they change their ways,” Trump told reporters of the current state of affairs between the U.S. and WTO. “They have been treating us very badly for many, many years and that’s why we were at a big disadvantage with the WTO.”

President Trump then warned, “We’re not planning anything now, but if they don’t treat us properly, we will be doing something.”

Reports have swirled that the United States could potentially leave the WTO. Axios reported details of what it said was a leaked Trump administration drafted bill to “declare America’s abandonment of fundamental World Trade Organization rules.”

Last week U.S. Trade Representative Robert Lighthizer rebuked countries that have issued retaliatory tariffs against the U.S., citing a WTO basis that Lighthizer refuted as “groundless legal theory.”

Follow Michelle Moons on Twitter @MichelleDiana