In a separate assessment of Mr. Kim’s health on Tuesday, the intelligence chief for South Korea’s conservative government said in a closed parliamentary session in Seoul that the leader appeared to be recovering quickly. According to Yonhap News, Kim Sung-ho, the director of the National Intelligence Service, told lawmakers that the North Korean leader had recovered enough to start performing his daily duties. Previous reports said he might have suffered a stroke.

Image A portrait of the North Korean leader, Kim Jong-il, in Pyongyang. Mr. Kim is said to be ill. Credit... Jo Yong-Hak/Reuters

That report came the same day that North Korea threatened to reduce South Korea to “debris” if it did not stop its “smear” campaign. The government was apparently enraged that Seoul had done nothing to stop human rights advocates from dropping anti-Kim leaflets from balloons flying over North Korean territory.

Although Mr. Aso did not provide further details about the North Korean leader’s condition, his comments were a rare instance of a national leader speculating publicly about Mr. Kim’s health. They did not seem to relate to any domestic political considerations, but Japanese leaders were upset this month when the Bush administration removed North Korea from the State Department’s list of state sponsors of terrorism.

Tokyo has long wanted to use the promise of removal from the terrorism list as leverage to force North Korea to be more forthcoming about the fate of Japanese citizens who were abducted many years ago. The prospect that the six-nation talks, in which Japan is participating, on dismantling the North’s nuclear program could be completed without resolving the abduction issue is anathema to the Japanese.