Chinese Ministry of Commerce spokesman Gao Feng speaks at a press conference in Beijing, days ahead of an imminent US-China trade war, on July 5, 2018.

BEIJING — China's official spokespeople are keeping quiet on trade talks with the U.S. amid growing uncertainty on when even a phase-one agreement can be reached.

"China believes if both sides reach a phase-one agreement, relevant tariffs must be lowered," Gao Feng, Ministry of Commerce spokesman said Thursday, according to a CNBC translation of his Mandarin-language remarks.

The comments reiterated the position Beijing has expressed in the last few weeks, since both countries indicated a rollback of tariffs would be part of a so-called phase-one agreement.

On Thursday, Gao noted both trade delegations remain in communication, but disclosed few additional details about the negotiations.

He did not provide a direct response when asked about China's view on additional U.S. tariffs, which are set to take effect Dec. 15. Gao also did not provide details on the unreliable entities list. The Commerce Ministry raised the threat of such a designation in late May, shortly after U.S. President Donald Trump's administration put Chinese telecommunications giant Huawei on a blacklist that effectively prevents it from buying from American suppliers.