Speaking at the WTO's closed-door dispute settlement body, the U.S. delegate opposed Hong Kong's decision to escalate the dispute by creating a WTO panel to rule on it, according to a copy of the speech.
However, Washington can only block it once and Hong Kong, a member in its own right at the 164-member body, can raise it again at the WTO next month.
The so-called "Made in China" dispute, opened by Hong Kong on Nov. 3, is over a U.S. rule stipulating that goods from the special administrative region of China now be marked as coming from China.
This requirement was announced by U.S. Customs and Border Protection in August, breaking with a former policy that allowed Hong Kong to be named as a place of origin.
The closed-door meeting of the WTO's dispute settlement body on Monday was Washington's first chance to weigh in on long-standing active trade disputes as well as deadlocked talks over revamping the WTO's top appeals bench.
Under former President Donald Trump, Washington blocked new judge appointments to the Appellate Body in a bid to force through reforms and paralysed its functions. However, the administration signalled no change in its position on the body at the Monday meeting and declined to support a proposal to appoint new judges.
While Biden's administration has officially taken over trade policy, observers say they do not expect any big changes until after Biden's trade nominee, Katherine Tai, is confirmed.
At the same meeting, South Korea filed an appeal against a WTO panel ruling from November which largely backed Japan in a dispute over steel duties, alleging "serious errors" in those findings.
However, it joins 16 other cases currently in legal limbo at the WTO appeals bench. Japan said in a statement it was "highly disappointed" by Seoul's decision to appeal.
(Reporting by Emma Farge, editing by Larry King)
