U.S. equity indexes opened lower as traders seek concrete evidence of progress in Washington’s trade talks with China as the next round of tariffs on Chinese imports loomed.

The Dow Jones Industrial Average dropped 79.47 points to 28,084.53 while the S&P 500 fell 6.28 points to 3,153.69 and the Nasdaq Composite Index lost 21.76 points to 8,683.42.

Both the New York Stock Exchange and Nasdaq will close at 1 p.m., while bond markets will close at 2 p.m.

China’s foreign ministry warned of consequences following President Donald Trump’s decision late Wednesday to sign a bill that supports pro-democracy protesters in Hong Kong.

“I signed these bills out of respect for President Xi, China, and the people of Hong Kong,” Trump said in a statement. “They are being enacted in the hope that leaders and representatives of China and Hong Kong will be able to amicably settle their differences leading to long term peace and prosperity for all.”

China’s Vice Foreign Minister Le Yucheng told U.S. Ambassador Terry Branstad that the bill represented “serious interference in China’s internal affairs and a serious violation of international law.”

The Chinese foreign ministry also stated that in passing the bill yhe U.S. "ignored facts, turned black to white, and blatantly gave encouragement to violent criminals who smashed and burned, harmed innocent city residents, trampled on the rule of law and endangered social order."

Concerns have been raised about the potential negative repercussions of the Hong Kong bill on ongoing trade talks between the U.S. and China.

“Markets are on a sort of ‘wait and hold’ in terms of that phase one trade deal,” David Riley, chief investment strategist at BlueBay Asset Management, told Bloomberg. “If there is a skinny deal, that will allow markets and risk assets to grind higher even if there is no real prospect of a phase two or subsequent detailed negotiation occurring this side of U.S. presidential elections.”

Michael Hirson, Asia director at Eurasia Group, said Trump's bill signing "will not derail trade negotiations".

"To be sure, Beijing is angered at the U.S. for interfering in what China considers its domestic affairs and for emboldening the protest movement," he said. "But some of China's anger over the bill is posturing for the domestic audience, and Beijing will not be so upset as to let this stand in the way of a truce over trade."

Adobe Analytics projected that U.S. shoppers spent $5.7 billion on Thanksgiving Day, a 16.4% rise over last year. Adobe expected $7.5 billion in spending for Black Friday, a 20.5% increase over the past year, and $9.4 billion in sales, a 19.1% rise, for Cyber Monday.

The Bank of Korea left interest rates unchanged at 1.25% after having enacted two cuts recently, citing concern about the global economy.

Soon after Audi announced layoffs, another German luxury carmaker Daimler AG said it plans to cut thousands of jobs by end of 2022 and lower staff expenses by 1.4 billion euros ($1.54 billion).

Energy firm Npower, a subsidiary of Germany’s E.On, will slash up to 4,500 jobs in the U.K. under a restructuring plan.

Overnight, Asian markets were down as the Hang Seng plunged 2.03% while Japan's Nikkei 225 dropped 0.49% and China's Shanghai Composite fell 0.61%.

European markets were mixed with the FTSE 100 down 0.38% while Germany's DAX rose 0.17% and France's CAC 40 was up 0.14%.

Crude oil futures slipped 1.09% to $57.02 per barrel and Brent crude lost 1.15% at $62.12. Gold futures edged up 0.03%.

The euro was down 0.15% to $1.0994 while the pound sterling fell 0.18% to $1.2890.