The exemptions, published late Friday in a notice by the US Customs and Border Protection office, cover various electronic goods including smartphones and components entering the United States from China, which are currently subject to a staggering additional 145 percent tariff.

Semiconductors are also excluded from the "baseline" 10-percent tariff on most US trading partners and the added 125-percent levy on China.

The exclusions narrow the range of sweeping 10-percent levies announced by President Donald Trump earlier this month, and the punishing additional rate on goods from China.

Trump has targeted China especially with his "reciprocal tariffs" meant to address practices Washington deemed unfair, most recently introducing a new 125-percent tariff on goods from the world's second-biggest economy that took effect this week.

The rate piled atop an earlier 20-percent levy Trump imposed over China's alleged role in fentanyl supply chains, and other existing tariffs from previous administrations -- taking the full figure to at least 145 percent for many products.

Many of the exempted products, including hard drives and computer processors, generally are not made in America.

While Trump has referred to tariffs as a way to bring manufacturing back to the United States, it will likely take years to ramp up domestic manufacturing.