Every time an image of U.S. President Donald Trump appears on TV in South Korea, 69-year-old Vietnam War veteran Chung Seung-jin solemnly salutes.

The U.S. flag Chung keeps in his home in Seoul gets similar respect every morning.

"I salute President Trump and the U.S. flag every day to show how much I trust him," Chung said as he attended a recent anti-North Korea rally in sweltering summer heat in downtown Seoul.