Asked aboard Air Force One whether he was open to North Korea's demand to be recognised as a nuclear state as a precondition for dialogue with Washington, Trump replied: "Well, I think they are sort of a nuclear power.

"When you say they have to be recognized as a nuclear power, well, they got a lot of nuclear weapons, I'll say that."

Trump is expected in South Korea on Wednesday for the Asia-Pacific Economic Cooperation (APEC) Forum.

US media have previously reported officials from his administration have privately discussed setting up a meeting between Trump and North Korean leader Kim, who he last held talks with in 2019.

Trump has said he hopes to meet Kim again -- possibly this year.

Kim said last month he had "fond memories" of Trump and was open to talks if the United States dropped its "delusional" demand that Pyongyang give up its nuclear weapons.

On Friday, South Korea's unification minister Chung Dong-young said he believed there was a "considerable" chance that Trump will meet Kim during his visit to the peninsula next week.

But a senior US official, speaking on condition of anonymity, told reporters in a call Friday that a meeting "is not on the schedule for this trip."

While no official announcements of the duo's meeting have been made, South Korea and the United Nations Command halted tours of the Joint Security Area (JSA) from late October to early November.

Kim and Trump last met in 2019 at Panmunjom in the JSA in the Demilitarized Zone (DMZ) separating the two Koreas -- the only place where soldiers from both sides face each other on a regular basis.

Minister Chung said North Koreans have been spotted "sprucing up" areas near the JSA for the first time this year -- cleaning, pulling weeds, tidying flower beds and taking photos.

Kim met Trump three times for high-profile summits during the US leader's first term.

The duo's last and impromptu meeting at Panmunjom was hastily arranged after Trump extended an invitation to Kim on Twitter a day prior.

That event saw the two leaders shake hands over the concrete slabs dividing North and South before Trump walked a few paces into Pyongyang's territory -- becoming the first US president ever to set foot on North Korean soil.

But talks eventually collapsed over just how much of its nuclear arsenal the North was willing to give up and what Pyongyang would get in return.

Since then, North Korea has repeatedly declared itself an "irreversible" nuclear state.