President-elect Donald Trump threatened to impose 100 percent tariffs on a group of developing countries that includes Vladimir Putin’s Russia and Xi Jinping’s China unless they commit to the U.S. dollar as a reserve currency.

“The idea that the BRICS are trying to move away from the dollar while we watch is OVER,” he wrote on Truth Social on Saturday, referring to the bloc that also includes Brazil, India, China, South Africa , Iran, Egypt, Ethiopia and the United Arab Emirates.

“We require these countries to commit to neither creating a new BRICS currency nor supporting any other currency to replace the mighty US dollar, otherwise they will face 100 percent tariffs and should expect to refrain from selling in to say goodbye to the wonderful USA. “Economy.”

The BRICS countries have been toying with the concept of “de-dollarization” since last year, in which they would rely on alternatives to the U.S. dollar for global trade, including conducting more trade in their local currencies.

Putin, in particular, has come out in favor of the idea after massive sanctions were imposed on Russia for ordering a full-scale invasion of Ukraine – a violation of international law, experts and the UN chief said.

According to ING, the BRICS countries control 42 percent of global central banks’ foreign exchange reserves.

Economists have expressed skepticism that they could succeed in creating their own currency that could compete with major reserve currencies such as the dollar, euro and pound sterling. “Nothing changes that the BRICS will replace the US dollar in international trade, and any country that tries should say goodbye to America,” Trump added in his Truth Social post.

There are at least some immediate ways the BRICS can reduce their dollar dependence.

Gold, its largest alternative to the U.S. dollar, accounts for just a tenth of its reserves, half the global average, ING analysts noted.

Trump threatened the BRICS a day after meeting Canadian Prime Minister Justin Trudeau, who flew to Florida and dined with him at Mar-a-Lago, to block a planned 25 percent tariff on all goods from Mexico and Canada. Trump says he will crack down on illegal immigration and drug trafficking in the US.

He also spoke to Mexican President Claudia Sheinbaum earlier this week about the proposal, although neither she nor Trudeau received a commitment.