By Upasana Bhat
Biden accuses Trump of "legitimising" North Korea as Trump describes his relationship with Kim Jong-un.
Observers suggest he may be trying to appear sympathetic in a difficult year for North Koreans.
By Paul Adams
As North Korea celebrates its military arsenal, leader Kim Jong-un says his country is "healthy and sound" in terms of coronavirus.
By Laura Bicker
BBC News, Seoul
Mr Kim's appearance at a party meeting comes after widespread speculation over his health.