President Donald Trump accuses China of unfair trade practices and is threatening to put new tariffs on as much as $450 billion of exports from China. The world's second biggest economy has vowed to retaliate.

A worsening tit-for-tat would be bad news for export powerhouses such as Taiwan, South Korea and Malaysia, which sell goods to China that are used to make products exported to the United States — from automobiles to consumer electronics.

"These are the industries that require technologies that come from many different directions," said Raymond Tsang, a Shanghai-based partner at consultant Bain & Company. "The supply chain ... is very complex."