A former top official of the International Atomic Energy Agency(IAEA) says that denuclearizing North Korea should involve step-by-step procedures but that it won't take a very long time.

Voice of America said Tuesday that it held a phone interview with former deputy director general of IAEA Olli Heinonen on Monday.

In the interview, he said that if all steps of the denuclearization properly proceed, he believes two to three years will be enough to complete the job.

The U.S. international broadcaster said the official attached a condition that North Korea must disclose all its production facilities related to its nuclear weapons program as well as all the nuclear materials it possesses, and that a verification process must also follow.

Heinonen was the lead official for inspections of North Korea's Yongbyon nuclear site during the first and second North Korean nuclear crisis in 1993 and 2002. He visited the North some 20 times over this period.
  

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