Upper House lawmaker Antonio Inoki plans to make a six-day trip to North Korea from June 21 to meet officials there, sources familiar with the plan said Tuesday.

The envisioned trip by the wrestler-turned-lawmaker, who has developed close ties with North Korea through sports exchanges, comes as Prime Minister Shinzo Abe is making efforts to reach out to North Korean leader Kim Jong Un.

Abe has said since May that he is willing to meet Kim without preconditions, having shifted from his stance that any summit should yield progress on the issue of Japanese nationals abducted by Pyongyang in the 1970s and 1980s.

Still, prospects are slim for a first-ever summit between the two leaders, with North Korean state-run media on Sunday calling the offer "brazen" and criticizing Japan for reaching out while maintaining its economic sanctions on the country .

According to the sources, Inoki, an independent lawmaker, is expected to leave Japan on June 21 and travel to North Korea via China. He previously visited North Korea in September last year.

As lawmakers need permission from the Diet to make overseas trips while it is in session, Inoki submitted his plan to the parliamentary group in the House of Councilors of which he is a member.

The current regular session ends on June 26.

Inoki was punished for making an unauthorized trip to North Korea in November 2013. He was barred from attending the Diet for 30 days.

The 76-year-old has repeatedly expressed his willingness to play a part in improving bilateral relations if requested by the Japanese government. Japan has no diplomatic relations with North Korea.