SEOUL - Republic of Korea (ROK) plans to extend a direct invitation to the leader of the Democratic People's Republic of Korea (DPRK), Kim Jong-il, to attend an international nuclear summit in 2012, a government official said Friday.

The official said ministries concerned will discuss details of the offer when President Lee Myung-bak returns home from his week-long European trip, and make a more concrete and direct offer to Kim Jong-il.

The move comes after Lee, during his visit to Berlin earlier this week, said he is ready to invite the DPRK leader to the nuclear summit scheduled to be hosted next March.

The president also made it clear that the DPRK should first show firm commitment to its nuclear disarmament before attending the upcoming global summit, and that the invitation will be extended only after the vow is made.

Pyongyang has rebuffed the offer, calling it "a ridiculous attempt to disarm the DPRK" in a statement carried by the state-run Korean Central News Agency. Seoul, in turn, responded to the dismissal, calling it "disappointing."

Seoul and Washington are expected to discuss follow-up moves to Lee's offer of invitation, with Stephen Bosworth, the US special representative for the DPRK, set to visit Seoul next Monday, according to local reports.