The International Atomic Energy Agency must redeploy its inspectors in North Korea to help with the denuclearization of the Korean Peninsula, Yukiya Amano, director general of the UN nuclear agency was quoted as saying by Kyodo news agency.

The death of North Korean leader Kim Jong il, announced on Monday, has plunged the region into uncertainty over the stability of the unpredictable state that is trying to build a nuclear arsenal.

UN inspectors were expelled from North Korea in 2009 and their return would be seen as a sign that the North may be serious about disarmament efforts.

"The redeployment of inspectors to the Yongbyong nuclear site is absolutely necessary for progress on denuclearization," he was quoted by Kyodo as saying.

"I have told IAEA headquarters to be completely thorough in gathering information. I want the IAEA to remain involved in this process."

The IAEA has shown its readiness to resume its verification activities in North Korea as soon as there is an agreement to this end by six-party talks aimed at compensating the North in return for giving up its nuclear weapons program.

Amano was in Tokyo to meet with Goshi Hosono, the minister in charge of dealing with Japan's nuclear crisis and other ministers.