SEOUL, April 3 (Xinhua) -- South Korea maintained a plan to denuclearize the Korean Peninsula in a "comprehensive and progressive" way, a senior official with the presidential Blue House said Tuesday ahead of the summit with the Democratic People's Republic of Korea (DPRK) later this month.

The unnamed Blue House official told local reporters that there had been nothing decided yet except a big picture that the denuclearization issue should be resolved in a comprehensive and progressive way, which President Moon Jae-in advocated, according to Yonhap news agency report.

"According to that direction, basic strategy and roadmap should be prepared before going through negotiations. It is now in the preparation phase," the official was quoted as saying.

The official noted that a big frame for the denuclearized Korean Peninsula would be set up through the inter-Korean summit before drawing an entire picture over the denuclearization through the DPRK-U.S. summit.

Moon and top DPRK leader Kim Jong Un agreed to hold their first summit on April 27 at Peace House, a building controlled by South Korea in the truce village of Panmunjom.

If held as agreed upon, Kim will become the first DPRK leader to set foot on the South Korean territory since the 1950-53 Korean War ended in armistice. The first and second inter-Korean summits were held in Pyongyang in 2000 and 2007, respectively.

U.S. President Donald Trump said he would meet Kim, the DPRK leader, by the end of May.