"After the five-year period, there will be limited pressure for a price hike."

He said the government is considering the best policy mix of various energy sources to meet the rising demand for cleaner and safer electricity.

The official also said South Korea has the highest density of nuclear stations in the world, which is three-fold that of Japan.

By 2030, Kori, a nuclear power station on the southeastern coast, will have nine reactors and the plant in Uljin will have 10.

Due to such high density, there will be always dangers of a nuclear accident in the region and the country, Lee said.

His comments came as a heated debate is erupting over a possible hike in electricity bills after President Moon Jae-in's pledge to push the country away from nuclear power.

In line with Moon's pursuit, the country's oldest nuclear reactor of Kori-i was shut down permanently in June, with the construction of two reactors temporarily suspended pending a final shutdown decision.

South Korea at present gets some 20 percent of its electricity from nuclear power.

The official said the government will make a constant effort to make it possible for renewable energy such as solar and wind power replace the current atomic power capacity step by step by 2079 when the last atomic plant, the Shin-Hanul 2, reaches the end of its operational life cycle. (Yonhap)