A source tells CNN an American has been detained in North Korea.
We've learned that the man, identified as Miller Matthew Todd, was taken into custody on April 10th.
A western diplomat tells CNN the 24-year-old tore up his visa at customs and appeared to go willingly with the North Koreans.
This comes as South Korea says the North may be preparing a nuclear weapons test, adding that it has completed all of the preliminary steps required to conduct such a test.
The timing comes as President Obama is visiting South Korea Friday, a trip North Korea has condemned.
Gordon Chang, author of "Nuclear Showdown: North Korea Takes on the World" is OutFront to break down what this latest news means.