Chinese officials are calling on US President Donald Trump to "completely cancel" his so-called reciprocal tariffs, as a trade war between the world's two biggest economies grinds on.

This week, Trump announced a 90-day pause on a host of global tariffs he had planned, but increased levies on Chinese imports to 145%.

"We urge the US to take a big step to correct its mistakes, completely cancel the wrong practice of 'reciprocal tariffs' and return to the right path of mutual respect," China's commerce ministry said in a statement.

The Trump administration seemed ready to offer a concession on Friday by announcing that some electronic products - including those produced in China - would be exempt.

But US Commerce Secretary Howard Lutnick told ABC News on Sunday that such exemptions would only be temporary.

He said the administration planned to impose such levies in a separate "semiconductor tariff", which he said would be announced at a later date.

"We need to have these things made in America," Lutnick said.