Reports that leader Kim Jong Il is ill and might have suffered a recent collapse were totally denied by North Korea officials on Wednesday who called them a “conspiracy plot,” media reports revealed.

Kyodo quoted Kim Yong Nam, North Korea's number two official, as saying there was "no problem" with Kim Jong Il.

"We see such reports as not only worthless, but rather as a conspiracy plot," Song Il Ho, North Korea's main negotiator in talks with Japan on normalizing ties, was quoted as saying in Pyongyang.

Earlier, an unnamed intelligence officer in South Korea's presidential office told the Yonhap News Agency Wednesday, "It is certain that Kim Jong Il is sick."

On Tuesday, a US official also said the reclusive North Korean leader appeared to have suffered health problems that could have been caused by a stroke.

Kim Jong Il's failure to appear at Tuesday's national parade celebrating the 60th anniversary of North Korea's founding further indicated the leader could be suffering health problems, the US official said, speaking on the condition of anonymity.

"It does appear that Kim Jong Il has had a potential serious health setback - potentially a stroke," the official said in Washington, adding that the ailment probably occurred within the past two weeks.

Seoul has detected a number of "unusual goings-on" in North Korea, including reports of Western and Chinese doctors flying into the capital, Pyongyang.

On Wednesday, South Korean President Lee Myung Bak called a top-level meeting to address speculation about the 66-year-old dictator, who reportedly has had heart problems and suffers from diabetes.