The U.S. and China imposed more tariff hikes on billions of dollars of each other's goods in an escalation of a battle over Beijing's technology policy that companies worry will chill global economic growth.

U.S. stocks skidded Thursday after President Donald Trump said he is canceling a planned meeting with North Korean leader Kim Jong Un. 

A Chinese state newspaper warned Monday that President Trump "could trigger a trade war" if he goes ahead with plans to launch an investigation of whether China is stealing U.S. technology.