SEOUL, April 20 (Xinhua) -- The Blue House of South Korea has been busily but shrewdly preparing for the upcoming summit with the Democratic People's Republic of Korea (DPRK), with just a week left to hold the historic third-ever meeting between leaders of the two sides.

The presidential office said Friday that it has opened the first-ever hotline of direct dialogue between leaders of the two Koreas, through which working-level officials made a test call for minutes earlier in the day.

It marked the first time since the 1950-1953 Korean War ended that the two sides established the hotline for leaders. To install the hotline, the two sides had met twice for working-level dialogues.

The hotline phones were placed inside the offices of South Korean President Moon Jae-in and top DPRK leader Kim Jong Un, enabling the two leaders to make a phone call at any time under emergency situations.

Moon and Kim have planned to have their first-ever conversation via the hotline next week before meeting face-to-face on April 27 at the Peace House, a South Korean building in the border village of Panmunjom.

Kim will become the first DPRK leader to step onto the South Korean territory since the Korean War ended with no signing of peace treaty. The Korean Peninsula remains technically at war, banning people of the two Koreas from visiting and contacting each other.

Local media speculations estimated that Kim would be greeted by Moon right in front of a concrete slab between blue buildings inside Panmunjom, which actually serves an inter-Korean border dividing the two Koreas.

During the working-level talks between the two sides on Wednesday to discuss security, protocol and media coverage for the summit, Seoul and Pyongyang agreed to live broadcast the Moon-Kim meeting from the very first scene in which the two leaders shake hands.

The two sides planned to rehearse the upcoming summit, respectively, next week as renovation works of the Peace House, which started from April 6, are scheduled to end Friday.

The South Korean side determined the list of officials who will accompany President Moon to the summit. It includes Im Jong-seok, chief of staff for the president; Chung Eui-yong, Moon's national security advisor; Suh Hoon, chief of the National Intelligence Service (NIS); and ministers of unification, defense, and foreign affairs.

On the key dialogue agenda for the third summit would be the denuclearized Korean Peninsula as the DPRK leader expressed his commitment to the nuclear disarmament.

According to a joint press release announced in early March after the visit by Moon's special envoys to Pyongyang for meeting with the DPRK leader, Pyongyang has no reason to possess its nuclear program if its security is guaranteed and military threats toward it are removed.

President Moon said Thursday that the DPRK was expressing its willingness for a complete denuclearization, noting that it would not be much difficult to reach an agreement in principle, among others, on the denuclearization and normalized relations between the DPRK and the United States through the inter-Korean and DPRK-U.S. summits.

Ending the war was forecast to be another main agenda at the summit as the Blue House confirmed its review over ways to switch the armistice agreement into a peace regime on the peninsula.

The three-year Korean War was paused by the armistice agreement. The Blue House said three- or four-way agreement would be possible to settle the issue.

According to the joint declaration released after the second inter-Korean summit in 2007, the two sides agreed to cooperate in and push for declaring an end to the war by holding a meeting among leaders of three or four nations directly concerned.

The ongoing developments are in line with China's proposal of a dual-track approach to the denuclearization talks on the one hand and efforts to establish a peace regime on the peninsula on the other hand.

A dual suspension, the other initiative offered by China to resolve the peninsula issues, is being unfolded. It requires the DPRK to halt nuclear and missile activities in exchange for the suspension of large-scale U.S.-South Korea war games.

The joint annual military exercises between South Korea and the United States were reduced in scale and shortened in period this year, while the DPRK paused its nuclear and ballistic missile tests amid a sudden period of detente.

The detente started with inter-Korean talks to discuss the DPRK's dispatch of athletes, artists and political delegations to the South Korea-hosted Winter Olympics in February.