The Dow Jones has lost 234,25 points on Tuesday.
North Korea conducted its sixth nuclear test on Sunday, which it said was of an advanced hydrogen bomb for a long-range missile, marking a dramatic escalation of the regime's stand-off with the United States and its allies.
Confirmation that euro zone business activity remained robust last month helped the pan-European STOXX 600 to claw back most of the 0.5 percent it lost on Monday amid worldwide condemnation of the previous day's nuclear test.
The escalating geopolitical tensions kept many investors on edge.
The expanded index S&P 500 has dropped 0.8 %, which is 18,70 points, 2457,85 points.
At 8:30am ET (1230 GMT), Dow e-minis were down 72 points, or 0.33 per cent, with 50,579 contracts changing hands. The Nasdaq composite slipped 5 points, or 0.1 percent, to 6,369.
Federal Reserve Governor Lael Brainard, an influential policymaker, said US inflation is falling "well short" of target so the central bank should be cautious about raising interest rates any further until it is confident that prices are headed higher. The S&P also snapped a six-day winning streak. The month of September, traditionally the most hard of the year, could be further complicated by a possible showdown in Washington around the debt ceiling, support for the Reuters news agency.
Before being able to tackle the issue of tax reform, Congress will have to adopt the budget and set the problem of the debt ceiling, all on the backdrop of new political turmoil after the decision of the us president, Donald Trump, to terminate the program put in place by his predecessor, Barack Obama, who has enabled hundreds of thousands of young undocumented immigrants stay in the United States.
European shares were expected to rise slightly after a slide on Monday.
MSCI's index of Asia-Pacific shares outside Japan was up 0.2 percent thanks to gains in Chinese shares, though many markets were in the red.
Insmed shares more than doubled after the company said its drug for the treatment of a rare and serious lung disorder met the main goal in a late-stage study.