China hits back with export controls, Canada and Mexico remain under threat. USPS closes then reopens "de minimis" small package loophole

Intended to protect domestic industries by raising import prices, they can pressure foreign nations accused of unfair trade practices. However, mainstream economists criticize tariffs as inefficient and harmful to consumers, who often bear the cost through higher prices.

Pope Francis, who is receiving treatment in hospital for a respiratory tract infection, will not appear in public on Sunday to lead his usual weekly prayer with pilgrims, the Vatican said.