The head of South Korea's National Intelligence Service(NIS) said there is internal resistance to the government's push to reform the state spy agency.

According to minor Open Democratic Party chief Choe Kang-wook, who met with NIS Director Park Jie-won at the National Assembly on Tuesday, Park said the agency must drop such notions if it wants to overcome its "dark past."

Choe added that Park had stressed to NIS employees that he is prepared to protect them from excessive political demands or interference, but they should abandon thoughts of protecting their vested interests.

During the 30-minute closed-door meeting requested by Park, the two men reportedly discussed the objectives and direction of NIS reform.

Park, who was appointed to his post last week, paid courtesy calls to the heads of the ruling Democratic Party(DP) and the minor Justice Party the previous day.

The NIS chief also plans to visit the main opposition United Future Party(UFP) and the minor People's Party later this month.