Investors also kept an eye on tech stocks, as the year's best-performing sector dropped more than 1 percent.
Elsewhere in commodities, the September crude contract was up 39 cents to US$49.56 per barrel, September natural gas advanced six cents at US$2.88 per mmBTU and the September copper contract declined two cents at US$2.93 a pound. The Nasdaq composite lost 96 points, or 1.5 percent, to 6,256. It was the biggest percentage loss since mid-June.
Markets reacted with dismay to his fresh warning Thursday that his earlier threat to unleash "fire and fury" on the reclusive nuclear-armed state may not have been "tough enough".
"Of course it's all come at a time when share markets are due for a correction, so North Korea has provided a ideal trigger", he added.
Titled "Reckless game over the Korean Peninsula runs risk of real war", the editorial suggested China will stay neutral if North Korea strikes first, but will intervene if the U.S.is the first mover. Discovery Communications fell 70 cents, or 2.9 percent, to $23.60.
Heading into Thursday, some 89 percent of the companies in the S&P 500 had reported quarterly results.
"There was some skittishness earlier but then some buyers stepped in", he said. The FTSE 100 index of leading British shares declined 0.6 percent.
U.S. president Donald Trump has thwarted the Dow Jones' nine-day winning streak with threats of "fire and fury" against North Korea as the Vix reaches a monthly high.
"If the USA and South Korea carry out strikes and try to overthrow the North Korean regime and change the political pattern of the Korean Peninsula, China will prevent them from doing so", the editorial's authors said.
The tensions, since Trump made his "fire and fury" comments on Tuesday, have wiped out almost $1 trillion from the global equity markets.
The S&P's record close on August 7 likely helped fuel its latest sell-off.
"For the time being, tensions seem to be going one way, and equity markets are losing ground because of it".
The S&P 500 dropped 1.4% to 2438.21, while the Dow Jones Industrial Average fell 204.69 points, or 0.9%, to 21,844.01. Brent crude, used to price worldwide oils, slid 80 cents, or 1.5 percent, to $51.90.
Politics lifted US defense stocks.
Shares of Walt Disney were down 4.23 per cent, the biggest drag on Dow, as investors doubted whether the company can succeed with its plan to launch its own streaming services rather than rely on Netflix to reach online viewers.
Nvidia soared 55% this year after notching the biggest gains in the S&P 500 in 2016. Small-company stocks fell more than the rest of the market.
Asian markets struggled again, with Japan's Nikkei feeling the pressure from the rise of the safe haven yen, which hit an eight-week high.
Macy's slumped 4.3% after reporting its 10th straight decline in a key sales measure. The stock lost $2.81 to $9.03.