A South Korean envoy who met with North Korean leader Kim Jong Un earlier this month briefed Japanese Foreign Minister Taro Kono on Monday about the talks, agreeing that Japan and South Korea will maintain pressure on the North until it takes concrete actions toward denuclearization.

"We agreed...that we will not repeat the mistakes of the past and will maintain maximum pressure on North Korea to make the abandonment of its nuclear and missile (programs) a reality," Kono said after his meeting over dinner in Tokyo with Suh Hoon, director of South Korea's National Intelligence Service.

After Suh and the other envoys met Kim in Pyongyang on behalf of South Korean President Moon Jae In, both Moon and U.S. President Donald Trump agreed to hold summits with Kim in the coming months.

"In order to bring forth meaningful results from North Korea at these summits, our three countries will take every opportunity to closely coordinate with each other, including Prime Minister Abe's visit to the United States early next month," Kono said.

Kono said he and Suh also affirmed that Japan and South Korea will work in close coordination on the issue of North Korea's abductions of Japanese nationals in the 1970s and 1980s.

Asked whether Kim made any mention to the envoys of the abduction issue or his willingness to hold a summit with Prime Minister Shinzo Abe, Kono said he "will refrain from saying anything other than what has already been announced."

Kono also refrained from confirming whether Kim had a specific message to convey to Abe, although he said Suh gave him a detailed explanation of the Pyongyang talks.

Japanese and North Korean leaders have not met since May 2004, when then Prime Minister Junichiro Koizumi met Kim's father Kim Jong Il in North Korea.

Abe is scheduled to meet Suh on Tuesday morning to hear about what went on at the Pyongyang talks.

Kono said he also explained to Suh a Japanese plan to assist the process of North Korea's denuclearization by covering the initial costs needed for the International Atomic Energy Agency to resume stalled inspections of North Korean nuclear facilities.

The Japanese government officially lists 17 of its citizens as having been abducted by North Korean agents and suspects Pyongyang's involvement in other disappearances of Japanese nationals.