U.S. manufacturers expanded at a slower pace in April, as measures of new orders, production and employment each slipped.

The Institute for Supply Management, an association of purchasing managers, says that its manufacturing index fell to 52.8 last month, down from 55.3 in March. Readings above 50 point toward an expansion in manufacturing. The sector has been reporting growth for 32 months.

ISM's survey of companies for the index is a sign that economic growth should continue, even though companies raised concerns about delays at the border between the United States and Mexico and the tariffs that President Donald Trump imposed on Chinese imports.