Nuclear-armed North Korea returned to the spotlight Tuesday after contradictory media reports said leader Kim Jong Un was in critical condition while others denied he was gravely ill — news that would have serious implications for Tokyo as Japan and the world continue to grapple with the deadly COVID-19 pandemic.

Citing unidentified U.S. officials, Bloomberg News reported that Kim, who has often been the subject of caricatures over his weight and reportedly unhealthy lifestyle, was said to be in critical condition after undergoing heart surgery last week.

The White House said it was unsure of his current condition, but was keeping a close eye on developments in North Korea.