The Dow Jones industrial average fell 30 points, or 0.2 per cent, to close at 14,810.31 Friday.
The broader Standard & Poor's 500 index fell five points, or 0.3 per cent, to 1,632.97. The Nasdaq composite fell 30 points, or 0.8 per cent, to 3,589.87
The market's reaction to speeches from Secretary of State John Kerry and President Barack Obama about Syria was muted.
Traders also digested a report from the U.S. Commerce Department that showed Americans' income and spending barely rose in July.
The S&P 500 fell 3.1 per cent in August, its biggest decline since May 2012, when it fell 6.3 per cent. However, the index is up 15 per cent for the year.