Donald Trump was ridiculed on social media Tuesday after proposing a new government agency to do a job that is already being done by another agency.

In a post on his Truth Social media platform, the president-elect announced plans to create an agency called the External Revenue Service that would collect tariffs and other revenue from foreign nations.

“We will begin charging those that make money off of us with Trade, and they will start paying,” Trump said in his post.

He compared the proposed agency to the Internal Revenue Service, which collects taxes from U.S. citizens and businesses.

The Associated Press notes that an act of Congress is required to create a federal agency.

But there’s another issue: The proposed duties of the “ERS” ― collecting duties and revenue from other nations ― are already handled by the Commerce Department and U.S. Customs and Border Protection.

Sen. Ron Wyden of Oregon, the top Democrat on the Senate Finance Committee, said in a statement that the proposed ERS was both “silly rebranding” and ”a multi-trillion-dollar tax hike on American families and small businesses to pay for another round of tax handouts to the rich.”

Trump’s plan ― and his apparent lack of knowledge about the government he was elected to run ― was also heavily ridiculed on social media.

This isn’t the first agency Trump has proposed.

During his first administration, he created the Space Force, a branch of the military devoted to fighting interplanetary wars.