If they are imposed, the tariffs will hurt American consumers most of all. The North American supply chain is integrated; nearly $1trn-worth of goods crossed the northern and southern borders of the United States last year.

By Joe Cash BEIJING (Reuters) -China attacked U.S. President-elect Donald Trump's pledge to slap additional tariffs on Chinese goods over fentanyl flows, saying his incoming administration was pushing the blame for America's opioid crisis onto China.

China announced Thursday that the U.S. had returned four people to China, including three citizens it said had been held for “political purposes.”

Americans Mark Swidan, Kai Li and John Leung would soon be reunited with their families in the United States after years in prison in China, the White House said.