Fears were growing for Kim Jong-un’s health today after a US official said the dictator could be in ‘grave danger’ after heart surgery – although South Korea has played down the reports.

Washington is monitoring intelligence that Kim is in a critical condition after his operation in North Korea, CNN quoted an unnamed US official as saying.

Kim, 36, was last seen at a government meeting on April 11, and was mysteriously absent from the celebration of his late grandfather Kim Il-Sung’s birthday on April 15.