Austin later condemned North Korea’s “irresponsible and reckless activities” during a joint press conference with Lee.
The South Korean government source said officials suspect it was a Hwasong-17, North Korea’s most advanced intercontinental ballistic missile that was first successfully tested on March 24.
That launch set a new standard for Pyongyang, recording the highest altitude and longest duration of any North Korean missile ever tested.
North Korea followed the presumed ICBM test Thursday with two short-range ballistic missile launches, according to South Korea and Japan.
Japanese Prime Minister Fumio Kishida speaks to the media in Tokyo following North Korea's weapons tests.