Updated

North Korea's reclusive, authoritarian leader appears well on the path to recovery from a stroke and in firm command of the communist country, the chief of South Korea's spy agency said Tuesday. But Japan's prime minister says Kim Jong Il likely is issuing his orders from a hospital bed.

The 66-year-old Kim disappeared from public sight in August. South Korean and U.S. officials said he suffered a stroke and underwent brain surgery, but North Korea has strenuously denied there is anything wrong with the man who is the subject of a cult of personality in the North.

Japanese Prime Minister Taro Aso told lawmakers in Tokyo on Tuesday that his government had information that Kim likely remains hospitalized.

"His condition is not so good. However, I don't think he is totally incapable of making decisions," Aso said.

The head of South Korea's National Intelligence Service, Kim Sung-ho, told lawmakers the North Korean leader is "not physically perfect" but appears to have recovered enough to run the country without difficulty.

The current leader inherited his country's leadership after his father's death in 1994 and has allowed no opposition and has named no known successors, leading to concerns of a power vacuum or military scramble for leadership should he die.

While Kim has been absent from view, tensions on the divided Korean peninsula have been especially high, with inter-Korean relations at a low and Pyongyang embroiled in an international standoff over its nuclear program.

North Korea's military issued a blistering warning to the South on Tuesday to stop its "confrontational" campaign to discredit Kim and the Stalinist nation, and threatened to reduce its rival to rubble.

"The puppet authorities had better remember that the advanced pre-emptive strike of our own style will reduce everything opposed to the nation and reunification to debris, not just setting them on fire," the North's military said in a statement carried by the state-run Korean Central News Agency.

The threat comes a day after North Korea demanded during brief talks at the Demilitarized Zone that South Korea halt the flow of propaganda across the border — just as South Korean activists dispatched leaflets urging North Koreans to rise up against their ailing, iron-fisted ruler.

Concerns over the leader's health grew frenzied when he missed a military parade marking the 60th anniversary of the day his late father, Kim Il Sung, founded North Korea.

Japan's Fuji television reported Monday that Kim's eldest son, Kim Jong Nam, flew recently to Paris to recruit a neurosurgeon to treat his father.

Aso said the French doctor later traveled to Beijing, perhaps en route to North Korea.

North Korea has sought in recent weeks to tamp down rumors about Kim's health with news reports and footage portraying the leader as active and able, attending soccer games and inspecting military units. The reports, photos and video are undated.

South Korean Defense Minister Lee Sang-hee said earlier this month that Washington and Seoul believe Kim is recuperating and remains in control. He hinted that the leader is aware of — and enjoying — the global speculation, saying: "If we show him too much attention, then we might spoil him."

Mercurial and reclusive, Kim has been known to stay out of public sight when tensions over North Korea's nuclear program are high.

He disappeared around the time the regime stopped disabling a reprocessing plant at Yongbyon in violation of a disarmament-for-aid deal over Washington's refusal to remove it from a list of nations that sponsor terrorism.

After a flurry of negotiations, Washington removed North Korea from the list and Pyongyang ended its boycott of the accord.

But South Korea's Gen. Kim Tae-young told a parliamentary committee that his military was prepared to attack suspected nuclear sites if the North tries to use its atomic weapons on the South.

On Tuesday, North Korea cited that threat, the defense minister's comment on Kim Jong Il and the continued stream of propaganda leaflets across the border as proof of a systematic "smear campaign" engineered by Seoul.

The two Koreas agreed in 2004 to stop decades of propaganda warfare at the DMZ but the South Korean government cites freedom of speech in its refusal to stop activists from sending leaflets across the border in huge helium balloons.

The two Koreas technically remain at war because the 1950-53 Korean conflict ended with an armistice, not a peace treaty.

On Tuesday, the National Intelligence Service said a North Korean soldier defected to the South through the heavily fortified DMZ — the second such defection in a decade. The soldier approached a South Korean guard post asking for asylum, an official said. She asked not to be named, citing agency policy.

More than 14,300 North Koreans have arrived in the South since the Korean War, according to South Korea's Unification Ministry, most traveling through China and Southeast Asia before landing in South Korea.