US President Donald Trump said on Thursday he would impose an added 10 percent tariff on Chinese imports while moving ahead with levies on Canada and Mexico next week, citing "unacceptable" fentanyl smuggling.

Trump had announced – then halted – sweeping 25 percent levies on Canadian and Mexican imports this month over illegal immigration and deadly fentanyl, with Canadian energy to face a lower rate.

But the month-long pause ends next Tuesday.

Following reporters' questions on whether he planned to proceed on the tariffs next week, Trump wrote on social media on Thursday that until the problem of fentanyl stops "or is seriously limited," proposed levies will happen as scheduled.

"China will likewise be charged an additional 10 percent Tariff on that date," he added.

He did not give further details on how the move interacts with an earlier levy he imposed on Chinese imports over Beijing's alleged role in the fentanyl supply chain, or how negotiations with China were proceeding.

China has voiced firm opposition to the US decision to impose tariffs on Chinese imports under the pretext of fentanyl-related issues.

China said it is one of the countries with the strictest drug control policies and the most rigorous enforcement in the world.

Trump added on Truth Social that an April 2 date for so-called reciprocal tariffs "will remain in full force and effect." (AFP/Xinhua)