North Korean leader Kim Jong II, 67, has life-threatening pancreatic cancer, according to Seoul's YTN television, the British newspaper Guardian reported on Monday.

Kim was diagnosed with cancer last summer increasing speculation his health is worsening after a reported stroke last year, YTN reported citing unidentified intelligence officials in South Korea and China.

The disease is threatening Kim's life and he is not expected to live more than five years, according to the report, raising concerns for North Korea's long-term stability.

The news came after Kim appeared in public last week looking thin, in an annual memorial of his late father Kim II Sung who founded North Korea. South Korea's currency, the won fell sharply on the news.

South Korea's National Intelligence Service could not confirm the report, according to the Guardian. Unification ministry spokesman, Chun Hae-sung, said he knew nothing of the claims and Reuters reported U.S. officials were unable to comment on it.