New Delhi, Feb. 13 -- South Korea's spy agency told lawmakers on Thursday that it believes the teenage daughter of North Korean leader Kim Jong Un is close to being designated as the country's future leader as he moves to extend the family dynasty to a fourth generation.

The assessment by the National Intelligence Service comes as North Korea is preparing to hold its biggest political conference later this month, where Kim is expected to outline his major policy goals for the next five years and take steps to tighten his authoritarian grip.

In a closed-door briefing, NIS officials said they are closely monitoring whether Kim's daughter - believed to be named Kim Ju Ae and around 13 years old - appears with him before thousands of delega...