US President Donald Trump said on Monday he will impose an additional 50% tariff on China if Beijing does not withdraw its retaliatory tariffs on the United States.

“Additionally, all talks with China concerning their requested meetings with us will be terminated! Negotiations with other countries, which have also requested meetings, will begin taking place immediately,” Trump said in a post on Truth Social.

China vowed on Tuesday to “fight to the end” if President Donald Trump follows through on a threatened 50% tariff hike, rejecting calls to drop its countermeasures and setting the stage for a high-stakes standoff between the world’s top two economies.

If neither side backs down, total new US levies on Chinese goods this year could rise to 104% by Wednesday, putting pressure on Beijing to respond as Chinese President Xi Jinping prepares to meet Spanish Prime Minister Pedro Sanchez ahead of a tour of Southeast Asia with global supply chains in jeopardy.

But with Trump’s previous tariff increases already squeezing Chinese exporters’ margins to the point of suffocation, further hikes would only serve to underscore Washington’s appetite for brinkmanship and its desire to cut China out of the world’s biggest consumer market as a matter of principle, analysts say.

“The US side’s threat to escalate tariffs against China is a mistake on top of a mistake, once again exposing the American side’s blackmailing nature,” China’s commerce ministry said in a statement.

Those Chinese levies had come in response to 34% “reciprocal” duties announced by Trump, which were in addition to 20% he imposed earlier this year, and result in the average U.S. tariff on Chinese goods rising to 76%.