The Trump administration has exempted a raft of consumer electronics from its punishing import tariffs, offering relief to US tech firms and partially dialling down a trade war with China.

A notice late Friday by the US Customs and Border Protection office said smartphones, laptops, memory chips and other products would be excluded from the global levies President Donald Trump rolled out a week ago.

The move came as retaliatory Chinese import tariffs of 125 percent on US goods took effect on Saturday, with Beijing standing defiant against its biggest trade partner.

The exemptions will benefit US tech companies like Nvidia and Dell, as well as Apple, which makes iPhones and other premium products in China.

And they will generally narrow the impact of the staggering 145 percent tariffs Trump has imposed this year on Chinese goods entering the United States.

US Customs data suggests the exempted items account for more than 20 percent of those Chinese imports, according to senior RAND researcher Gerard DiPippo.

Although listed among the exempted goods, semiconductors could still become a target of industry-specific tariffs Trump has suggested placing on imports from all countries.

Trump, over the weekend, noted that he would give a “very specific” answer to the question of any future semiconductor levies on Monday.