Pyongyang seems unprepared to address "outstanding issues of concern," including its missile and nuclear programs, as well as the abduction of Japanese nationals -- all of which are deemed important for the Japanese leader -- during talks with Tokyo, the Japanese ambassador to the United States said Monday.

Ambassador Shigeo Yamada clarified Japan's motivation for advocating a summit between Prime Minister Fumio Kishida and North Korean leader Kim Jong-un, as well as Kishida's guiding principle in proceeding with the summit, which draws contrasts with North Korea's proclaimed position on the summit.

"Prime Minister Kishida believes that if we can ever establish a productive relationship with North Korea, that will be beneficial to Japan and North Korea as well as to the region to establish stability in the region," Yamada said during an event hosted by the Washington-headquartered Center for Strategic and International Studies think tank.

"But at the same time, the prime minister's very clear principle is we have to see if we can resolve all the outstanding issues of concern," he added.

Yamada, however, raised doubts about North Korea’s willingness to address the issues at the negotiation table, referencing press statements from late March attributed to the North Korean leader's sister, Kim Yo-jong, and Foreign Minister Choe Son-hui as evidence supporting his assessment.

The spate of press statements clarified North Korea's stance, reaffirming its refusal to engage in discussions regarding its missile and nuclear development, as well as the abduction of Japanese nationals during the 1970s and 1980s, during dialogue with Japan.

"So far, the recent statements from North Korea indicated that they are not ready to deal with those outstanding issues of concern. So we'll see how things will develop," Yamada said.

Yamada clarified that a key precondition for proceeding with the Japan-North Korea summit would be putting North Korea's nuclear and missile programs, as well as the abduction issue, on the dialogue table as agenda topics.

"I think, for the prime minister, it is very important to resolve outstanding issues of concern, I mean, missile issues, nuclear issues and the abduction issue. So those continue to be a very important issue for the prime minister," he said.

The potential of such a summit has garnered attention, fueled by Kishida's statement that his government was making "high-level approaches" to arrange a meeting with Kim to resolve "outstanding issues." The statement was made during his interview with CNN, released Sunday, before the prime minister's state visit to the US this week.

The ambassador's comments highlighted the discrepancies between Tokyo and Pyongyang in terms of agenda topics for the summit, lowering expectations for the occurrence of the summit, which has not taken place since 2004.

“To resolve those issues, if North Korea is forthcoming, (the) prime minister is ready to have a dialogue with the North Korean side," Yamada said. "Under his direct instructions, we'll see how the North Korean side will react."

The North Korean foreign minister claimed that North Korea "has nothing to solve as regards the 'abduction issue' insisted by Japan and, moreover, it has neither the responsibility nor the will to make any effort for it," in a press statement issued March 29 in response to Kishida's parliamentary speech the same week.

Choe also emphasized that the North Korea-Japan dialogue "is not a matter of concern" to North Korea, adding that North Korea "will not allow any attempt of Japan to contact the former."

Kim Yo-jong touted the refusal of any further negotiations with Japan, dismissing Kishida's remarks on the North Korea-Japan summit as "politically motivated" in a separate statement on March 26.

Kim asserted that Japan should not bring up North Korea's nuclear and missile issues for discussion. Kim warned Japan not to "interfere in and take issue with the exercise of sovereignty belonging to the DPRK's legitimate self-defense," referring to North Korea by its official name, the Democratic People's Republic of Korea.