Lee Myung-Bak, the president of South Korea president, said he believes that the Korean peninsula will one day unite during a visit to Oslo, Norway.

"We are the only divided nation in the world and it is inevitable that we [will] come to peaceful reunification at some point," he said.

"Nuclear weapons or military might is not a way for North Korea to overcome the current problem," in a direct plea to Pyongyang to relinquish its atomic program as demanded by the UN.

In August, the South Korean government estimated that reunification with the North could cost up to 249 trillion won ($221 billion) – more than one-sixth the value of South Korea’s GDP for 2011 – in the first year alone, excluding medical costs, pensions and other benefits were factored in.

North and South Korea technically remain at war since 1953, when their civil war ended in a truce instead of a peace treaty.