The son of a Japanese woman abducted by North Korea in 1978 has released letters he has exchanged with former North Korean agent Kim Hyong Hui since their meeting in South Korea in March.

Koichiro Iizuka, 32, said he was disclosing the letters sent and received in July and August because he worries that the government of Prime Minister Yukio Hatoyama may not address the abduction issue as aggressively as had the long-ruling Liberal Democratic Party.

Kim, who learned Japanese in the North from Iizuka's mother, Yaeko Taguchi, sent a letter in August saying "I was very glad that we were able to meet. I still remember the feeling of such an emotional experience," according to Iizuka.

Kim was traveling on a false Japanese passport with a fellow North Korean agent when they planted a bomb almost two decades that brought down a Korean Air jetliner, killing everyone onboard.