(Reuters) - Imports into the U.S. could be down at least 20% year-over-year in the second half of 2025 due to U.S. President Donald Trump's sweeping tariffs on several trade partners, a forecast by the National Retail Federation showed on Wednesday.

With Trump's reciprocal tariffs coming into effect on Wednesday, along with additional tariffs on China, imports are expected to drop dramatically beginning next month, according to the forecast based on data collated by research firm Hackett Associates for the U.S. trade body.

"Retailers have been bringing merchandise into the country for months in attempts to mitigate against rising tariffs, but that opportunity has come to an end with the imposition of the 'reciprocal' tariffs," said Jonathan Gold, NRF vice president for supply chain and customs policy.

The current forecast would bring the first half of 2025 to 11.73 million 20-foot container units (TEU), down 2.9% year over year. The trade body had previously forecast imports to rise 5.7% in the first half prior to the April tariff announcement.

Trump's reciprocal tariffs included a new baseline 10% U.S. tariff on goods from all countries and higher reciprocal tariff rates for countries that his administration says have high barriers to U.S. imports.

As a result, retailers from Nike to Best Buy ( BBY ) are likely to be forced to raise prices as Trump's eye-watering tariffs hit key manufacturing hubs including China, Vietnam and Indonesia.

The tariffs, including Trump 104% tariffs on China as well as a retaliatory 84% duty on U.S. imports from Beijing, rattled global markets on Wednesday, unleashing a selloff in U.S. assets amid fears of a global recession.

Based on expectations for a dramatic decline in the second half of the year, total 2025 cargo volume could post a net decline of 15% or more unless the situation changes, the report added.

"At this point, retailers are expected to pull back and rely on built-up inventories, at least long enough to see what will happen next," Gold said.