Trump to WSJ: Korea actually used to be a part of China

US President Donald Trump has enraged South Koreans by saying in an apparently offhand comment after meeting with Chinese leader Xi Jinping that “Korea actually used to be a part of China”.

The historically inaccurate sentence from a Wall Street Journal interview bumps up against a raft of historical and political sensitivities in a country where many have long feared Chinese designs on the Korean Peninsula.

It also feeds neatly into long-standing worries about Seoul's shrinking role in dealing with its nuclear-armed rival, North Korea.

In Seoul, protesters gathered outside China's embassy to make their point, while the South Korean foreign ministry issued a public rebuke to the US president. South Koreans believe he was prompted to say it by China's President Xi Jinping after their meeting in Mar-a-Lago.

South Korea fears China wants to make it part of its sphere of influence by rewriting history and turning past Korean kingdom into “vassal state”.

Ahn Hong-seok, a 22-year-old college student, said that if Trump is a person capable of becoming a president, I think he should not distort the precious history of another country.'