"China has requested WTO dispute consultations with the United States in regard to new tariff measures applied by the United States on goods originating in China," the organisation said in a statement.
New 10 per cent tariffs imposed by the Trump administration on all Chinese imports took effect on Wednesday AEDT.
China responded by announcing tariffs of 15 per cent on imports of liquefied natural gas (LNG) products and coal from the US.
In a statement cited by the WTO, China said the measures appeared to be inconsistent with US obligations under the agreement that led to the creation of the trade body, pointing to the discriminatory nature of the tariffs.
"China reserves the right to raise additional measures and claims regarding the matters identified herein during the course of consultations and in any future request for the establishment of a panel," the Chinese statement said.
It did not detail what measures those could be.
If the dispute is not resolved after 60 days, "the complainant may request adjudication by a panel," the WTO said.
Experts then assess whether the tariffs are compliant with WTO rules, in a procedure that takes several months.
If the arbitrators rule in China's favour, Beijing can, under WTO rules, impose tariffs itself to the extent that it has suffered damage as a result of the US tariffs.
Trump on Saturday ordered tariffs on goods from Mexico, Canada and China, demanding they staunch the flow of fentanyl - and, in the case of Canada and Mexico illegal immigration. He later froze tariffs against the two North American countries but went ahead with those on China.
Since December 2019, the WTO's dispute settlement system has been effectively paralysed following the collapse of its Appellate Body which has the final say on disputes.
Trump's first administration and that of Joe Biden blocked the appointment of new judges to the Appellate Body over what they saw as judicial overreach in disputes. The body is unable to function with less than three judges.
Separately, the US Postal Service said it would again accept parcels from China and Hong Kong, reversing a 12-hour suspension after Trump scrapped an exemption used by retailers including Temu, Shein, and Amazon to ship low-value packages duty-free to the US.
The about-face added to the growing confusion among retailers and express shipping firms over how to deal with Trump's new 10 per cent tariff on imports from China and his closure of the "de minimis" duty exemption for packages valued at under $US800, with the stated aim of stopping the flow of fentanyl and precursor chemicals into the US.
Major international shippers promised to maintain deliveries, but disruptions may still occur as the USPS works out how tariffs on small packages would be collected in tandem with the US Customs and Border Protection department.
FedEx, meanwhile, suspended its money-back guarantee on overseas shipments.
"We're all running around like headless chickens at this moment in time, trying to second-guess what's going to happen. And in two weeks' time we may be back to normal," said Martin Palmer, co-founder of Hurricane Commerce, a cross-border ecommerce data provider.
About 1.36 billion shipments entered the United States using the de minimis provision in 2024, up 36 per cent from 2023, according to CBP data. Reuters reporting has found that drug traffickers have exploited the exemption to bring fentanyl and its precursor chemicals into the country unscreened.
with Reuters
38°C