At the close of trading in NY, the Dow Jones Industrial Average was down 33.08 points, or 0.15%, to 22,085.34.
United States markets fell on Wednesday morning, spooked by rising tension between the U.S. and North Korea. The S&P 500, a broader gauge of USA companies, fell 0.24 percent to 2,474.92.
Wall Street declined on Tuesday after a late afternoon selling spree in response to President Donald Trump's statement saying North Korea "will be met with fire and fury" if it threatens the US.
The back-and-forth came on the heels of reports the U.S. intelligence community has determined North Korea has successfully produced a miniaturized nuclear warhead that can fit inside its missiles.
The Dow closed down 33 points, at 22,085.34.
Overall, second-quarter results have been stronger than expected with analysts now expecting S&P 500 earnings to have expanded 11.8%, up from 8% at the start of July, Reuters reported.
Following two relatively quiet days on the U.S. economic front, trading on Wednesday may be impacted by a report on labor productivity and costs in the second quarter.
Oil service stocks showed a significant move to the downside on the day, dragging the Philadelphia Oil Service Index down by 1.9%. The Nasdaq composite climbed 30 points, or 0.5 percent, to 6,414.
The Labor Department also said unit labor costs rose by 0.6% in the second quarter following an upwardly revised 5.4% spike in the first quarter.
Apple (AAPL.O) pared gains after rising as much as 1.91 percent to an all-time high and provided the biggest boost to all three indexes, while healthcare stocks such as Johnson & Johnson (JNJ.N) were the biggest weight on the S&P.
Brokerage stocks are among the few groups seeing notable weakness, with the NYSE Arca Broker/Dealer Index down by 1 percent.
U.S. crude oil for September delivery fell 0.4% to $US49.17 a barrel, its third decline in four sessions.
In overseas trading, stock markets across the Asia-Pacific region moved mostly lower during trading on Wednesday.
A majority of the major sectors have moved lower on the day, although most are showing relatively modest moves to the downside. The Nasdaq composite fell 13 points, or 0.2 percent, to 6,370.
Meanwhile, the major European markets moved modestly higher over the course of the session.
The Standard & Poor's 500 index rose 7 points, or 0.3 percent, to 2,488.
Nevertheless, traditional safe havens jumped, with the benchmark 10-year US note yield hitting its lowest level since June 28 and gold futures surging more than 1 percent.
In the bond market, treasuries have moved sharply higher due to their appeal as a safe haven amid geopolitical tensions.