Wall Street's major indexes fell on Thursday as trade-sensitive stocks were hit by a fresh round of tariffs in the trade dispute between the United States and China.
Despite ongoing talks, the two countries imposed tariffs on $16 billion worth of each other's goods.
Shares of industrial giants Caterpillar Inc and Boeing Co, which have been bellwethers of trade sentiment, were among the biggest drags on the Dow. Caterpillar shares fell 2.0 percent, and Boeing shares fell 0.7 percent.
In the S&P 500, the technology sector was the sole gainer, rising 0.2 percent. But it pared gains late in the session, sending the tech-heavy Nasdaq into negative territory along with the S&P and the Dow.
"It's tough to say how far this will go," Brendan Erne, director of portfolio implementation at Personal Capital in San Francisco, said of the US-China trade dispute. "It could be a fairly long and winding road, but at least it's encouraging that both sides are talking now."
The Dow Jones Industrial Average fell 76.62 points, or 0.3 percent, to 25,656.98, the S&P 500 lost 4.84 points, or 0.17 percent, to 2,856.98 and the Nasdaq Composite dropped 10.64 points, or 0.13 percent, to 7,878.46.
The energy index fell 0.5 percent and the materials index fell 0.7 percent, the biggest percentage drops among the S&P's major sectors, as prices of crude oil and metals fell due to trade war worries.
The potential political fallout from the legal woes of two former advisers to US President Donald Trump also weighed on investor sentiment.
Data from the US Labor Department indicated the labour market was holding firm despite trade tensions as jobless claims fell for the third straight week.
Investors said they were keeping a close eye on the meeting of US central bankers in Jackson Hole, Wyoming, where Federal Reserve Chair Jerome Powell will speak on Friday. His speech will be watched for clues on monetary policy after minutes from the most recent meeting indicated that the Fed would raise interest rates soon.
Shares of Hormel Foods Corp fell after the meat producer attributed its underwhelming quarterly results to Chinese tariffs, which Hormel said have led to domestic oversupply and lower prices. Hormel shares ended the session down 3.1 percent.
Shares of Victoria's Secret owner L Brands Inc plunged 11.4 percent to reach their lowest level since March 2011 after the retailer cut its full-year profit forecast.
Declining issues outnumbered advancing ones on the NYSE by a 1.93-to-1 ratio; on Nasdaq, a 1.42-to-1 ratio favoured decliners.
The S&P 500 posted 25 new 52-week highs and one new low; the Nasdaq Composite recorded 137 new highs and 32 new lows.
Volume on US exchanges was 5.57 billion shares, compared with the 6.35 billion average over the last 20 trading days.