17692
These isotopes are monitored to ensure compliance with nuclear test ban treaties , and to confirm nuclear tests by states such as North Korea .
 location: North Korea
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
 Entities: North Korea 
Answer:
 location: North Korea