North Korean leader Kim Jong Il has put his youngest son in charge of the country's spy agency in a move aimed at handing the communist regime over to him, a news report said.

Kim visited the headquarters of the State Security Department in March, along with his 26-year-old third son, Kim Jong Un, and told agency leaders to "uphold" the son as head of the department, the newspaper reported on Tuesday, citing an unnamed source.

Kim Jong Il, pictured right on this poster, has appointed Kim Jong Un, left, as head of North Korea's spy agency. Credit:AP

Kim also told department leaders to "safeguard comrade Kim Jong Un with (your) lives as you did for me in the past," and gave them five foreign-made cars, each worth some $US80,000 ($A100,743), as gifts, the mass-market daily said.

It said Kim visited a college that educates spy agents last month and made similar remarks there.