North Korean leader Kim Jong-un has written a letter to South Korean President Moon Jae-in, promising to meet frequently in 2019 to discuss the denuclearisation of the Korean Peninsula. The two leaders held three meetings, including one in Pyongyang, this year.

Kim “expressed an intention to meet with Moon frequently in 2019” to pursue peace and “solve the issue of denuclearising the peninsula together”, Moon’s spokesperson Kim Eui-kyeom said on Sunday, AFP reported. Kim also “expressed a strong determination to visit Seoul while watching the future situation”, he added. It is not clear how the letter was delivered.

Moon welcomed Kim’s letter. “I welcome chairman Kim’s intention to solve together the issue of denuclearisation ... by meeting frequently even next year,” Moon said in a statement.

Kim also sent a “letter-like” message to United States President Donald Trump, which was delivered on Friday, Reuters reported. The letter was related to US-North Korea talks and adopted a conciliatory tone, Chosun Ilbo reported.

Kim and Trump had met in Singapore in a historic summit in June, with the North Korean leader promising to denuclearise the peninsula.

However, relations between Pyongyang and Washington have soured again. Earlier this month, the US said it has introduced sanctions on three North Korean officials, including a top aide to leader Kim Jong-un, for alleged human rights abuses. In response, Pyongyang said this could “block the path to denuclearisation on the Korean peninsula forever”.