The Dow Jones Industrial Average slipped 178.66 points or 0.67 per cent to 26 564.84. The S&P 500 was down 12.79 points or 0.44 per cent to 2 916.88 Xinhua news agency reported.
The Nasdaq Composite Index decreased 13.07 points or 0.16 per cent to 7 973.88.
Trade-sensitive stocks Caterpillar and Boeing dropped 1.50 per cent and 1 per cent respectively around midday.
Fears that an escalation of trade frictions between Washington and its key trading partners may have negative impact on the global economy continued to rattle investors analysts noted.
On economic data the Chicago Fed National Activity Index (CFNAI) was unchanged at +0.18 in August from July rate the Chicago Federal Reserve Bank announced on Monday.
The CFNAI is a weighted average of 85 existing monthly indicators of national economic activity. A positive index reading corresponds to growth above trend and a negative index reading indicates growth below trend.
--IANS pgh/
