A World Trade Organization (WTO) arbitrator on Friday gave Washington until August 22 to implement a prior ruling faulting the anti-dumping measures taken against Chinese products.
The WTO's Dispute Settlement Body ruled last May that some of the US anti-dumping practices were inconsistent with international trade rules.
Arbitrator Simon Farbenbloom said in a report that it was "reasonable" to expect the US to implement the ruling within 15 months.
"The reasonable period of time for implementation will expire on 22 August 2018," he said.
The case dates back to December 2013, when China filed a dispute against the US, taking issue with the way Washington assesses whether exports have been "dumped" at unfairly low prices onto the US market.
The use of anti-dumping duties are permitted under international trade rules as long as they adhere to strict conditions, and disputes over their use are often brought before the WTO's Dispute Settlement Body.
In this specific case, China alleged that the US, in violation of WTO rules, was continuing a practice known as "zeroing", which calculates the price of imports compared to the normal value in the US to determine predatory pricing.
In October 2016, a panel of WTO experts found largely in China's favor in the case, including on the issue of "zeroing".
The US, which has repeatedly lost cases before the WTO over its calculation method, said in June 2017 that it would implement the panel's recommendations, saying it would do so within a "reasonable" time frame.
This prompted China to ask the WTO to appoint an arbitrator to set an end date.