Biden and Yoon also extended an offer of help to Pyongyang, which has recently announced it is in the midst of a Covid-19 outbreak, a rare admission of internal troubles.
The ongoing COVID wave, declared last week, has fuelled concerns over a lack of vaccines, inadequate medical infrastructure and a potential food crisis in the country of 25 million
North Korea fired a submarine-launched ballistic missile Saturday, Seoul said, its second missile launch in three days, after the United States warned Pyongyang could be preparing for a nuclear test