US President Donald Trump said on Wednesday that the United States might have to “cancel” trade agreements made with the European Union, Japan, South Korea, and others if it loses the tariff case currently before the Supreme Court.

He warned that losing the case would cause “great suffering” for the United States.

Trump told reporters at the White House that his administration will ask the Supreme Court to overturn a recent appellate court ruling that deemed many tariffs illegal. He expects his administration to win the case.

He added, “We made a deal with the European Union where they pay us nearly a trillion dollars. You know? They are happy. It’s done. All those deals are finished… I think we will have to cancel them.”

This is Trump’s first comment hinting at the possibility of voiding agreements with major trading partners if the Supreme Court upholds last Friday’s ruling.

Trump said canceling tariffs would be costly, although trade experts point out that tariffs are paid by importers in the US, not companies in the countries of origin.

On Wednesday, the Trump administration took the tariff case to the Supreme Court, asking the justices for a swift ruling affirming the president’s authority to impose broad trade sanctions under federal law.

The government urged the court to overturn the appellate court’s decision that most tariffs imposed by Trump were illegal under the Emergency Powers Act.

The federal appellate court had kept the tariffs in effect for now, but the administration requested urgent Supreme Court intervention in a petition filed Wednesday evening, obtained by the Associated Press.

Most economists warn that tariffs are likely to increase inflation in the United States.