South Korean President Park Geun-hye pledged Friday to make "substantial" preparations for potential unification with North Korea, a day after the North's leader, Kim Jong-un, offered conditional summit talks with her.

Park said South Koreans have a historic task to overcome a seven-decades-long division and open a new era of unification.

The Korean Peninsula was divided into the capitalistic South and communist North after its liberation from Japan's 1910-45 colonial rule.

"The government will do its best in making substantial preparations and implementation to ensure that unification will become a reality, not a dream," Park said in a New Year's meeting with hundreds of senior officials at the presidential office.

In his New Year address on Thursday, the North's leader said he is willing to hold summit talks with Park if proper conditions are created.

"Depending on the mood and circumstances to be created, there is no reason not to hold the highest-level talks," Kim said.

South Korea welcomed Kim's gesture as "meaningful" and urged North Korea to show its sincerity through action, not just words.

It remains unclear whether the two Koreas can hold a summit as Kim's overture was conditional on Seoul shifting its policy toward Pyongyang, including a halt to its annual joint military exercises with the United States.

Park's two liberal predecessors held summit talks with the then North Korean leader Kim Jong-il, the late father of the current leader Kim, in Pyongyang in 2000 and 2007, respectively. Kim Jong-il died of heart failure in 2011.

Park has made repeated pitches for unification, calling it a "bonanza" for South Korea as well as a blessing for neighboring countries.

However, North Korea has long suspected that Seoul could be plotting to absorb Pyongyang, a claim denied by South Korea. (Yonhap)