There are reports that Beijing and Washington are close to signing a "Phase 1" of the US-China trade deal, but Beijing even said several weeks ago that signing a whole agreement with the Trump administration was unlikely.

US officials told Taiwanese diplomats that semiconductors produced by TSMC, then bought by Huawei, were ending up in Chinese missile guidance systems that were aimed at Taiwan, reported Finacial Times (FT).

"US officials often have conversations with Taiwan interlocutors about the security and end-use of their technology supply chains. We have similar general export control and non-proliferation conversations with many partners," the official said.

"In this particular case, we have a partner that is under a direct military threat from China, and is also one of the few places that produce certain technologies China needs to support its military ambitions."