South Korean President Lee Jae Myung is leaning on promises to "Make America Shipbuilding Great Again" during his first official U.S. trip, as the two allies wrangle over other details of their trade and security agreements.

Donald Trump suggested on social media that the U.S. might stop doing business with South Korea, but in a meeting with President Lee Jae Myung, no tension emerged.

The US president says it "seems like a Purge or Revolution" in South Korea, as President Lee visits the White House.