WASHINGTON/NEW YORK -- China has detained a former Canadian diplomat in what is seen as retaliation for the arrest of Huawei Technologies' chief financial officer in British Columbia, triggering the U.S. to consider issuing a warning for its citizens traveling to the Asian country.
The move marks a rapid deterioration of relations, after U.S. President Donald Trump and Chinese President Xi Jinping agreed on a trade war truce in Argentina on Dec. 1.
