"The escalation of the geopolitical situation between the US and North Korea is beginning to rattle investors' nerves as was witnessed in the VIX index yesterday", said Peter Cardillo, chief market economist at First Standard Financial. Oil prices were headed higher.
S&P 500 e-minis were up 1.5 points, or 0.06 percent, with 300,073 contracts traded.
The Dow Jones industrial average lost 50 points, or 0.2%, to 22,032.
The Nasdaq composite slumped 135.46 points, or 2.1 percent, to 6,216.87. The Russell 2000 index of smaller-company stocks gave up 4.02 points, or 0.3 percent, to 1,410.15.
The market slide accelerated slightly in the last half-hour of trading as President Donald Trump denounced North Korea's nuclear program.
"We've had enough": Conservatives relish the "fury" in Trump's talk
In national media interviews , Senator Dan Sullivan said Congress holds final authority when it comes to preemptive war strikes. Madeline Bordallo, D-Guam, the territory's non-voting U.S.
With Japan and South Korea also warning North Korea, investors are taking a step back to see what is happening before chipping in back, Bakhos said.
The remarks followed a new report asserting that USA intelligence has assessed that Pyongyang has successfully produced a nuclear warhead that can fit inside its missiles.
The markets may benefit from bargain hunting, as some traders look to pick up stocks at reduced levels following the pullback seen over the past few sessions. The Nasdaq composite fell 35 points, or 0.5 percent, to 6,336. Biotech companies Celgene and Amgen lost 3.8 percent and 2.6 percent, respectively.
FINANCIALS FALLING: Several financial sector companies also helped pull down the market.
Retail results are also on investors' mind as the second-quarter earning season winds down.
India vs SL, 3rd Test: KL Rahul & Shikhar Dhawan lead charge
This young team has been chasing leather this whole series - India scored 600, 240/3 and 622/9 in three innings in Galle and SSC. Dhawan made a 123-ball 119, including 17 boundaries, and shared a 188-run first-wicket stand with Lokesh Rahul (85).
Large retailers Macy's and Kohl's tumbled on Thursday after they reported another quarter of shrinking sales. On the Nasdaq, 1,685 issues fell and 615 advanced favoring decliners. Kohl's also declined, sliding $3.62, or 8.6 percent, to $38.31.
BONDS: Bond prices rose. The yield on the 10-year Treasury note slipped to 2.21 percent from 2.25 percent late Wednesday.
The Canadian dollar was trading at an average price of 78.67 cents United States, down 0.04 of a USA cent. Brent crude, the global standard, lost 23 cents to $52.14 a barrel in London. Brent crude, used to price worldwide oils, gained 10 cents to $52.24 in London.
The rhetoric, which began late Tuesday and continued into Friday, cracked the calm that has enveloped the market for months and interrupted stocks' march higher. Germany's DAX fared better, trading only 0.2 percent lower at 11,989. The FTSE 100 index of leading British shares was 0.6 percent lower.
The rouble was little changed at 60.1 against the dollar and firmed 0.05 percent to 70.7 versus the euro. Australia's S&P/ASX 200 edged down almost 0.1 percent.
SoundCloud secures its 'largest financing round,' names former Vimeo exec new CEO
We just closed out the first decade and created a really unique platform that impacts global music every day", said Ljung. I'm excited to also announce that this new partnership also brings talent to our SoundCloud family.