South Korean President Moon Jae-in will discuss ways to denuclearise the Korean Peninsula when he meets North Korean leader Kim Jong-un this week, Moon's chief of staff said Monday.

Im Jong-seok said it will mark a rare opportunity to discuss the issue with the North Korean leader himself, S. Korea's News Agency (Yonhap) reported.

"Just until recently, denuclearisation had been an agenda item for talks between the North and the United States," Im told a press conference in Seoul, one day before the South Korean president was set to embark on a three-day trip to N. Korea. "Now, denuclearisation is a key issue (at the inter-Korean summit)," Im said.

"This issue cannot be discussed at the working level and even if it is discussed (at the working level), no agreement can emerge from such talks," he added, highlighting the importance of talks on the issue between the leaders.

Moon will have at least two occasions to discuss ways to denuclearise the Korean Peninsula with the North Korean leader, Im noted. Im said Moon's North Korea trip will focus on three agenda items.

The first is to improve and develop inter-Korean relations, the second is to mediate and promote North Korea-US talks for denuclearisation of the Korean Peninsula, and the third they will discuss reducing military tensions and ending the threat of war.

Moon's trip to Pyongyang comes amid an apparent deadlock in the U.S.-North Korea denuclearisation talks. Washington insists on the need for maximum sanctions and pressure against the North until the communist state fully denuclearises while Pyongyang is said to be asking for early rewards for the steps it has taken so far.

Part of the inter-Korean summit in Pyongyang will be broadcast live in Seoul, marking the first time in history for any event in the communist state to be broadcast live in South Korea, Im noted.

The Moon-Kim summit will mark the third of its kind since Moon took office in May 2017. The two leaders held their first two meetings on April 27 and May 26 in the border village of Panmunjom that sits directly on the inter-Korean border.