A ranking official at the South Korean presidential office says the government has explained to North Korea in detail the content and purpose of the conditional invitation which President Lee Myung-bak extended to North Korea’s leader Kim Jong-il.

President Lee said in Berlin this week that he is willing to invite the North Korean leader Kim Jong-il to the Nuclear Security Summit in Seoul next year if Pyongyang makes a firm pledge toward denuclearization. The official said although South Korea’s stance has been clearly delivered, North Korea has not responded yet.

Presidential spokeswoman Kim Hee-jung told reporters Wednesday that the presidential office has confirmed the delivery of the South Korean government’s real intent to the North and is hoping for more concrete discussions between the two Koreas.