SEOUL, South Korea may send special envoys to North Korea if necessary to arrange or ensure the success of their summit next week, according to the presidential office Cheong Wa Dae, reported Yonhap news agency.

"The possibility of sending the head of the National Intelligence Service (NIS) or National Security Office chief Chung Eui-yong always remains open if necessary while preparing for the summit," Cheong Wa Dae chief of staff Im Jong-seok told a press briefing Tuesday.

Chung and the NIS chief, Suh Hoon, travelled to Pyongyang early last month as special envoys of South Korean President Moon Jae-in.

There, the two South Korean envoys held an unprecedented meeting with North Korean leader Kim Jong-un, who offered to meet the South Korean leader and US President Donald Trump to discuss his country's denuclearisation.

The Moon-Kim meeting is set to be held next Friday. Trump has said he will likely meet the North Korean leader in late May or early June.

Im said the Moon-Kim summit will be a historical event as it will be the first time for a North Korean leader to set foot on South Korean soil.

The third inter-Korean summit is set to be held on the South Korean side of the joint security area of Panmunjom inside the heavily-fortified demilitarised zone.

"It is an important point to us because depending on the outcome of the summit, it may lead to the establishment of regular dialogue (between the two Koreas) at Panmunjom," Im said.

Earlier, the unification ministry said 360 rounds of inter-Korean dialogue have been held at Panmunjom, accounting for more than half of 655 inter-Korean talks held since the division of the two Koreas at the end of the 1950-53 Korean War.

Inter-Korean dialogue was suspended for years under two conservative South Korean administrations. Talks resumed at the start of this year after Pyongyang agreed to take part in the 2018 Winter Olympic Games held in South Korea.

Further portending continued dialogue, the two Koreas have agreed to establish a direct hotline between their leaders.

Im said the direct phone line will likely be set up Friday for possible trials before the inter-Korean summit.

The Cheong Wa Dae official insisted the upcoming summits may provide a rare, if not the first-ever, chance to finally rid the communist North of its nuclear weapons.

"We believe the South-North Korea summit will be important in that it will be followed by a North Korea-US summit, and may possibly lead to a South-North-US summit," he said.

Im noted the North had agreed to denuclearise on various occasions in the past but that such agreements had not been realised, partly due to a lack of US support or consent.

"If we say we put in so much effort into dialogue between the South and the North, we put in three times as much effort into communicating with the US," he said.

"We are hoping that holding the South-North Korea summit and the US-North Korea summit successively will be the key to addressing fundamental issues."

The Cheong Wa Dae official also said the Moon-Kim summit may be different from the two previous inter-Korean summits in that it will focus on fundamental issues.

Seoul and Pyongyang have agreed to put three issues at the top of the agenda for the inter-Korean summit.

They are: denuclearisation of North Korea, establishment of permanent peace on the Korean Peninsula and improvement in inter-Korean ties