US President Donald Trump said Tuesday he doesn't know about the health condition of North Korean leader Kim Jong-un amid reports he may be seriously ill.

"These are reports that came out, and we don't know. We don't know," Trump said at a White House coronavirus press briefing. "I can only say this: I wish him well. Because if he is in the kind of condition that the reports say, that the news is saying, that's a very serious condition, as you know, but I wish him well."

Trump said he doesn't place "too much credence" in any report put out by CNN. Citing an unidentified US official, CNN first reported that the US is looking into intelligence that Kim is in "grave danger" after a surgery.

"They came out with very, very serious medical reports. Nobody's confirmed that," he said.

Asked about possible successors to Kim in the dynastic regime, Trump declined to weigh in.

"I don't want to ask him that. I haven't asked him that. It's not my purpose to tell you that in all fairness, but I hope he does well," he said, adding he has had a "very good relationship" with Kim.

Asked if he plans to reach out to Kim to check on his condition, Trump left open the possibility.

"I may, but look, I just hope he's doing fine," he said. "I'd like to see him be well, and we'll see how he does. Again, I don't know that the reports are true."

The CNN report came after the Daily NK, a South Korean internet news outlet specializing in North Korea news, said Kim has been receiving medical treatment following a cardiovascular procedure.

South Korean officials dismissed reports about Kim's health problems, saying no unusual signs have been detected in the North that suggest something's wrong with his health.

Speculation has arisen about what happened to Kim since he apparently skipped an annual visit to the Kumsusan Palace of the Sun on the occasion of the 108th birthday of his late grandfather and state founder Kim Il-sung last Wednesday.

Kim was last seen April 11 in state media reports presiding over a political bureau meeting of the ruling Workers' Party, calling for "strict national countermeasures to thoroughly check the infiltration of the virus."

Trump claimed Saturday that he recently received a "nice note" from Kim. North Korea denied shortly afterward that any message had been sent.

The two men have maintained personal correspondence despite stalled negotiations on dismantling North Korea's nuclear weapons program.

They met three times -- once in 2018 and twice in 2019 -- to try to reach a deal on denuclearizing the North in exchange for US sanctions relief, but negotiations have faltered since the second summit in February 2019 ended without an agreement. (Yonhap)