Pyongyang, December 21 (KCNA) -- Kim Hyon Hwan, head of the Institute of Independent Ideology in the United States, issued a condolatory statement over the demise of leader Kim Jong Il.

No words can express the bitter grief at the fact that Kim Jong Il, chairman of the National Defence Commission, died of great mental and physical strain on a running train, the statement said.

Always in simple jacket he engaged himself only in work all his life as a soldier and an official serving President Kim Il Sung before passing away, it noted, describing his life as a brilliant one dedicated to the country and the people.

We express deep condolences over the demise of the chairman who had energetically worked around the clock for national reunification and global independence all his life, it said, adding that he will always live in the mind of mankind.

Kim Suk, a member of the Federation of Koreans in the U.S., too, made public a condolatory statement.

It is hard to believe that Kim Jong Il passed away, the statement said, mourning his demise in humblest reverence.