WASHINGTON: President Donald Trump's threat to impose 10% tariffs on the remaining $300 billion of Chinese imports from Sept. 1 will hit consumers at the start of the important back-to-school buying season, four large retail trade associations warned on Thursday.

The Footwear Distributors and Retailers of America said the tariffs would jack up prices for consumers and could have a chilling effect on hiring.

"President Trump is, in effect, using American families as a hostage in his trade war negotiations," the group's president, Matt Priest, said in a statement.

Stephen Lamar, executive vice president of the American Apparel & Footwear Association, told Reuters the tariffs would be "hugely disruptive," and would drive prices for consumers higher since they cannot easily be absorbed in the supply chain.

Lamar said Trump uses tariffs as a negotiating tool, but he had made good on previous threats in regard to Chinese imports.

"We're telling people they should assume the tariffs will take effect on Sept. 1," he said, adding that the group's members were shocked and surprised that Trump had not allowed resumed US-China trade talks to proceed before threatening additional tariffs.

The measure will hit US consumers far harder than Chinese manufacturers, who produce 42% of apparel and 69% of footwear purchased in the United States, Lamar said.

The measure will trigger more retailers to seek sources in other countries, where capacities are limited, which will further increase costs, he said.

Additionally, competitors that are not affected by the tariffs could see an opportunity to increase prices, he added.