LOS ANGELES (Reuters) -U.S. imports of containerized goods in September fell 8.4% from the year earlier, including a 22.9% drop in goods from China, amid ongoing trade ructions from President Donald Trump's tariff policies, data released on Thursday showed.

U.S. seaports handled 2.31 million 20-foot equivalent units (TEUs) of container cargo last month, the third-highest September volume on record despite being a decline from last year, supply chain technology and data provider Descartes said.

With most holiday merchandise delivered earlier than usual and tariffs continuing to rise, monthly import cargo volume at the nation's major container ports is forecast to fall below the 2 million TEU mark for the remainder of the year, the National Retail Federation (NRF) and Hackett Associates said.

"This year's peak season has come and gone, largely due to retailers frontloading imports ahead of reciprocal tariffs taking effect," said Jonathan Gold, NRF's vice president for supply chain and customs policy.

More tariffs - 25% on upholstered furniture regardless of country and the same rate on kitchen cabinets and bathroom vanities - are set to take effect next week and increase in January, NRF said. A tariff increase on imports from China, delayed by 90 days in August, also is scheduled for November 10, unless a deal is reached or Trump decides on another delay.

"Ongoing volatility in U.S. tariff policy is creating significant economic uncertainty," Hackett Associates founder Ben Hackett said.

Reflecting market demand, the Drewry East-West Contract Rate Index - an average of contract rates paid by more than 100 multinational shippers, including retailers like Walmart ( WMT ), on 17 major ocean routes - fell 3% in the 12 months to September, the first year-on-year reduction since July 2024.

To be sure, U.S. imports have held up generally well under unprecedented tariff pressures.

Year-to-date volume through September was 1.9% ahead of the same period in 2024.

Still, China's share of total U.S. imports slid to 33% in September from 34.5% in August, Descartes said.

China-origin imports tumbled to 762,772 TEUs in September - with aluminum, footwear and electric machinery logging the steepest drops. Toys and sporting goods, as well as footwear and apparel were also down. The overall result marks a reversal from the short-lived rebound in July and August, and highlights importer sensitivity to tariff policy, Descartes said.

Imports from South Korea, Taiwan, Hong Kong, Germany and Italy also notched year-over-year declines last month, Descartes said.

Meanwhile, several Southeast and South Asian countries expanded market share, the firm said.

Imports from Indonesia, Thailand, Vietnam and India all increased.

Nevertheless, month-over-month data showed a nearly across-the-board slowdown in Asian trade momentum, Descartes said.