Markit Economics released its preliminary manufacturing purchasing managers' index (PMI) for the U.S. on Friday. The U.S. preliminary manufacturing purchasing managers' index (PMI) declined to 52.9 in August from 53.8 in July, missing expectations for an increase to 54.0. It was the lowest level since October 2013.

A reading above 50 indicates expansion in economic activity.

The decline was driven by a slower expansion in output, new orders and employment.

"According to survey respondents, the strong dollar continued to put pressure on export sales and competitiveness, while heightened global economic uncertainty appeared to have dampened client spending both at home and abroad. Alongside this, manufacturers of investment goods widely cited growth headwinds from the slump in capital spending across the energy sector," Markit Senior Economist Tim Moore.