What the Americans are doing it's called strategic ambiguity, basically confirming and denying at the very same time. The same method is used by the Israeli when asked about their nuclear program.
Fortunately for Taiwan, Biden has confirmed that the US will stand by Taiwan if attacked.
Mind to readers that Biden has some dementia and he could slip his tongue when he said that the US will defend Taiwan. But the point is crystal clear.
As for WH statements, it's mainly diplomatic. In which will evaporate oncw hostilities broke out.