About five minutes into trading, the Dow Jones Industrial Average was down 0.3 percent to 26,509.15.

The broad-based S&P 500 slid 0.4 percent to 2,942.42, while the tech-rich Nasdaq Composite Index shed 0.8 percent to 8,805.45.

US indices lost about one percent on Thursday after President Donald Trump's surprise announcement of a 10 percent punitive tariffs on $300 billion in Chinese imports. Major bourses in Europe and Asia have lost more than two percent since the announcement.