President-elect Trump warned Panama in a Truth Social post Saturday night that the United States would demand the canal’s return if Panama did not stop collecting exorbitant royalties.

“The fees Panama charges are ridiculous, especially given the extraordinary generosity the United States has given Panama. This complete ‘rip-off’ of our country will stop immediately,” he wrote, calling the canal “an important He called it “a nation.” assets. “

“We will never allow it to fall into the wrong hands! It was not given for the benefit of others, but simply as a token of our cooperation with Panama. If the moral and legal principles of this generous donation are not upheld, we will demand the full return of the Panama Canal, no questions asked,” Trump continued.

President Trump criticized former President Jimmy Carter for giving away the canal, calling it a foolish decision.

Mr. Carter signed an agreement with then-Panamanian military junta leader Omar Torrijos in 1977, beginning the transfer process that culminated in a complete transfer to the Panama Canal Authority in 1999. According to Go to history.com. (Related: Panama Canal could dry up, wreaking havoc on consumers around the world)

However, before the Carter Treaty, the United States signed the Hey-Bunau-Varilla Treaty of 1903. The treaty granted the United States “use, occupation, and control” of the canal lands for “construction, maintenance, operation, sanitary, and protection.” According to To Duke University Press.

According to History.com, the U.S. actually granted Panamia to then-territorial owner Colombia after Colombia rejected the U.S. attempt to overtake France’s failed attempt at building a canal. He is said to have supported the sovereignty revolution.

This infrastructure project was the most expensive in American history at the time, and remains an important aspect of American trade. As President Trump noted in his post, 70% of all shipping through the canal is to or from U.S. ports.

President Trump also cited China’s growing influence in Latin America as a potential threat to ports.

“Panama alone controls it, not China or anyone else,” he wrote. “We will never allow it to fall into the wrong hands!”