BEIJING (AP) — Was President-elect Donald Trump signaling a shift in U.S.-China relations when he referred to Taiwan's leader as "president" following a phone call this past week or was it an unintentional misstep?

His phone conversation with Tsai Ing-wen (tsy ying-WEN') was a breach of long-standing tradition that risks enmity from China, but a longtime China watcher says he can't yet be sure of the meaning.

Douglas Paal, a former director of the American Institute in Taiwan which unofficially represents U.S. interests in Taipei, said it was too soon to judge whether Trump was going to lead that shift, or if the incident was just a "complicated accident."

Paal, now vice president for studies at the Carnegie Endowment for International Peace, says: "Beijing will watch closely to see which it is."