Stocks resumed their steep pullback on Thursday as the latest concessions from the White House on President Donald Trump's controversial tariff policies failed to calm rattled investors.

The Dow Jones Industrial Average traded 516 points lower, or 1.2%, after falling more than 600 points at session lows. The S&P 500 shed 2%, while the Nasdaq Composite lost 2.9%.

Thursday's declines come as U.S. tariffs on Canadian, Mexican and Chinese imports have rocked financial markets after taking effect this week. Canada and China each responded with retaliatory levies of its own, while Mexico said it would unveil measures over the weekend. The Nasdaq has dropped more than 4% week to date, while the Dow and S&P 500 have slid around 3.1% and 3.8%, respectively.

Thursday marked a return to selling after the White House's announcement of a one-month delay for tariffs on automakers that sell cars that comply with the United States-Mexico-Canada Agreement spurred a recovery rally on Wednesday. That gave hope to investors expecting the levies to be further walked back, in turn mitigating the expected hit to the U.S. economy.

Trump on Thursday announced that more Canadian and Mexican goods made in accordance with the USMCA agreement would receive a one-month extension on the taxes. But that news did not deliver the same upward momentum in the market seen in the prior session as uncertainty around the policy swirled.

Concerns mounted on Thursday afternoon after Treasury Secretary Scott Bessent argued in favor of tariffs, leaving investors questioning how far the White House would be willing to go in making compromises on the embattled policy over the long term. Investors appeared fatigued by the barrage of statements from administration members and changes to tariff policy in recent days.

"To the extent that another country's practices harm our own economy and people, the United States will respond," Bessent said during an Economic Club of New York event. "This is the America-first trade policy."

Bessent also described Canadian Prime Minister Justin Trudeau as a "numbskull," while saying the administration was focused more on Main Street than Wall Street. The S&P 500 hit its lowest point since early November in the session.

"You're just having confusion," said Keith Lerner, chief market strategist at Truist. "That confusion is permeating into the day-to-day swings of the market."

A continued unwind of the popular artificial intelligence trade that has boosted the market for more than a year also hurt stocks on Thursday.

Notably, chipmaker Marvell Technology dropped more than 17% after the company issued mixed first-quarter guidance. Other semiconductor builders such as ON Semiconductor, Taiwan Semiconductor and Nvidia also slid.

On top of that, a string of recent economic reports raised alarm that Trump's policies could hinder the U.S. economy. Those came ahead of Friday's closely watched jobs report.

The Federal Reserve's Beige Book and the Institute for Supply Management's manufacturing reading both indicated fear of rising input costs because of the tariffs. Data from Challenger, Gray & Christmas released Thursday showed layoff announcements soared to 2020 highs, which the outplacement firm found was driven by Trump and billionaire Elon Musk's efforts to shrink the federal government's workforce.