FedEx freight volumes from China to the US “deteriorated sharply” in May after President Donald Trump launched his trade war, hitting demand for consumer shipments on the company’s most profitable route.

Shares in FedEx, the express parcel delivery company long seen an economic bellwether, fell nearly 6 per cent on Wednesday after the company said that it expected trade between the countries to remain “pressured” in the current June-to-August quarter.

“We just simply cannot predict how that is going to play out,” Brie Carere, chief customer officer said, as she told investors on a results call, adding that the China-US route represented 2.5 per cent of the company’s revenue and that the trade lane was its most profitable intercontinental route.