Markit Economics released its preliminary manufacturing purchasing managers' index (PMI) for the U.S. on Thursday. The U.S. preliminary manufacturing purchasing managers' index (PMI) fell to 53.8 in May from 54.1 in April, missing expectations for a rise to 54.5. It was the lowest level since January 2014.

A reading above 50 indicates expansion in economic activity.

The Markit Chief Economist Chris Williamson said that export sales dropped for two straight months. That has not seen for two years, he added.

"Unless production growth revives there is a worry that payroll growth will slow as companies seek to boost productivity," Williamson pointed out.

According to the survey, manufacturers say that the stronger U.S. dollar is hurting demand for exports.

The preliminary new orders index declined to 54.2 in May from 55.3 in April.

The preliminary output index was down to 55.0 in May from 55.3 in April, the lowest level since December 2014.