has a new tariff headache, courtesy of U.S. President Donald J. Trump.

Trump on Friday threatened a round of “massive increase” of tariffs on Chinese imports to the U.S., according to a Truth Social post. The new threat centers on a dispute regarding rare earth minerals. Trump says that China wants to impose export controls, calling the move “Trade hostility” in the post.

He also noted in the post that America’s relationship with China over the past six months has been a “very good one,” saying this new move on trade was a “surprising one.” Trump said he was to meet with China’s President Xi Jinping in two weeks, but now suggest that the meeting might be cancelled.

Trump’s new threat sent the equity markets reeling on Friday over fears of a new tariff hike. At the close, the Dow Jones Industrial Average fell 878.82 points, or 1.9 percent, while the S&P 500 was down 182.60 points, or 2.7 percent.

Footwear stocks also fell on Friday, joining the overall market decline. Shoe stocks posting the largest declines were Caleres Inc., down 10.7 percent, or $1.42, to $11.85; Genesco Inc., off nearly 7 percent, or $1.95, to $26.08; Allbirds Inc., down 5.8 percent, or 36 cents, to $5.90, Steve Madden Inc., declining 5.1 percent, or $1.74, to $32.25 and Crocs, declining nearly 5 percent, or $3.69, to $76.70. Among the retailers, shares of Shoe Carnival fell 6.8 percent, or $1.36, to $18.59, Academy Sports and Outdoors Inc. was down 6.1 percent, or $3.22, to $49.38, and Dick’s Sporting Goods Inc. declined 5.5 percent, or $12.20, to $211.62.

The U.S. and China in August agreed to a second 90-day extension for ongoing bilateral trade talks. That gave footwear firms, and even consumers, a bit of breathing room for the holiday season. The first pause began in May.

Under the temporary pause, tariffs remain at 30 percent, down from 55 percent, but could have risen to as high as 145 percent for some goods if the pause had not been extended. As recently as late last month, one source told Footwear News that talks between the U.S. and other countries — including China and Vietnam, where much of the footwear industry produces its shoes — continue to be ongoing. And the thinking was that when the current extension is set to end mid-November, the two countries would agree to yet another 90-day extension.

What happens next is anyone’s guess.

“This news poses a significant threat to U.S. retailers and brands that still rely heavily on China for footwear production. China remains a dominant source for shoes imported into the U.S. Any disruption — whether tariffs, trade tensions, or logistics shocks — can quickly drive-up costs and create uncertainty for consumers,” said Matt Priest, president and CEO of the Footwear Distributors and Retailers of America.

Priest emphasized that while shoe firms have “learned from past challenges” and have become more resilient through shifts in their sourcing networks, the footwear supply chains are still highly complex and that china’s scale and efficiency would be difficult to replace.

Steve Madden Ltd.’s chairman and CEO Edward Rosenfeld noted as much when the company posted second quarter earnings results in July.

Earlier this year, the company made some quick moves to exit China when Trump got re-elected, knowing that tariffs would be high on his agenda. That shifted for all companies, not just footwear, when Trump disclosed on April 2 that he was implementing reciprocal tariffs.

In the second quarter conference call, Madden’s CEO said the company moved some production for fall back to China where it was deemed to be too difficult to ensure on-time delivery, product quality and/or reasonable pricing in an alternative country.

Madden had moved a lot of product out of China to Brazil, but that was before Trump in July added a 40 percent levy on Brazilian imports on top of the existing 10 percent tariff, bringing the total duty rate to 50 percent. The Trump administration justified the high rate on the criminal prosecution of former President Jair Bolsonaro, saying that reflected an economic emergency. There are now reports that Brazilian President Luis Inácio Lula da Silva earlier this week had asked Trump to lift the 40 percent duty.

All this tariff uncertainty makes it hard for shoe companies to plan their business and cost infrastructure. And shoe firms that don’t have the flexibility and extensive sourcing and supply chain that Madden has have many tough challenges ahead.

Trumps says that tariffs are good, with the benefits including both reduced trade deficits and increased revenue. But tariffs also cause inflation for consumers due to higher prices when companies pass along those cost increases. And consumers might end up with fewer options along the way.

Vietnam saw footwear exports to the U.S. fall in September, one month after the new tariff increase was implemented in August. The country is also the dominant producer of athletic performance shoes, becoming the beneficiary when firms moved out of China during Trump’s first term after he began hiking tariff rates on Chinese imports. Vietnam’s customs data from the Ministry of Finance showed that exports fell 27.3 percent to $611 million from $840 million in August.

The current tariff rate is 40 percent, comprised of the new 20 percent rate on top of the existing 20 percent rate. A preliminary trade deal between the U.S. and Vietnam was disclosed in July, but the finer points of the agreement still need to be ironed out. One source told Footwear News last month that those talks remain “ongoing.”