Stocks and commodities including copper and iron ore fell after a surprise drop in China's exports bolstered concern about the slowing growth in the world's second-largest economy.
China's exports sank 18.1 percent in February from a year earlier, according to General Administration of Customs data on the weekend. As a result, copper futures for May delivery shed 1.5 percent to US$3.0355 a pound in afternoon trading on the Comex in New York, extending Friday's slide of about 4 percent.
In afternoon trading in New York, the Dow Jones Industrial Average fell 0.35 percent, the Standard & Poor's 500 Index slipped 0.14 percent, while the Nasdaq Composite Index edged 0.13 percent lower.
"Any poor news from China is always going to hit short-term market sentiment, especially in the mining sector, and fears of slower growth will hit base metals," IPR Capital director Steven Mayne told Reuters.
Slides in shares of Boeing, last down 2.3 percent, and those of Verizon, last down 0.9 percent, led declines in the Dow.
Boeing was dragged lower after saying it would inspect wings for cracks on undelivered 787s, and after a 777 flown by Malaysian Airline System disappeared over the ocean three days ago.
"News of the wing and inspections likely lower first quarter deliveries, plus the 777 aircraft incident in Asia will likely weigh on the Boeing stock this week," Peter Arment, an analyst at Sterne, Agee & Leach, told Bloomberg News.
In Europe, the Stoxx 600 Index ended the session with a 0.5 percent drop from the previous close. The UK's FTSE 100 fell 0.4 percent, while Germany's DAX gave up 0.9 percent. France's CAC 40 added 0.1 percent.
Concern about the ongoing crisis in Ukraine keeps weighing on markets worldwide.
Meanwhile, Philadelphia Federal Reserve Bank President Charles Plosser reiterated his concern that the US economy might be stronger than policy makers anticipate and suggested the Fed should accelerate the tapering of its monthly bond-buying programme.
On Friday, a report showed American employers added a higher-than-expected 175,000 jobs, while January's jobs gain was revised up. The unemployment rate rose to 6.7 percent, from 6.6 percent.
"I expect that the unemployment rate will reach about 6.2 percent by the end of 2014, and, if anything, that may prove too pessimistic," Plosser said in a speech in Paris. "Given the recent trends, an unemployment rate below 6 percent is certainly plausible."
"Reducing the pace of asset purchases in measured steps is moving in the right direction, but the pace may leave us well behind the curve if the economy continues to play out according to the FOMC forecasts," Plosser said.