*CHINA RETALIATES AGAINST TRUMP TARIFFS WITH LEVIES OF UP TO 15% *CANADA ISSUES 25% RETALIATORY TARIFF ON US IMPORTS, WILL REMAIN IN PLACE UNTIL US TRADE ACTION IS WITHDRAWN *Trump's 25% tariffs on Mexico and Canada took effect, ending decades of relative free trade between US and its North American neighbors; along with a doubling of duties on Chinese goods to 20%. *The tariff actions, which could upend nearly 2.2 trillion in two-way annual U.S. trade went live *Mexico to announce response on Tuesday