Long-threatened tariffs from U.S. President Donald Trump have plunged the country into a trade war abroad — all while on-again, off-again new levies continue to escalate uncertainty.

Former Philippine President Rodrigo Duterte said he takes full responsibility for his administration's "war on drugs", in a video message posted on his Facebook account, as he braces for a legal battle at the International Criminal Court.

President Trump said he would double steel and aluminum tariffs on Canada amid a fight with Ontario over higher electricity costs for Americans.