North Korea does not appear to be ready to deal with "outstanding" matters with Japan, including the issue of Japanese nationals abducted by Pyongyang decades ago, Tokyo's top envoy to the United States said Monday.

Ambassador Shigeo Yamada made the remarks, referring to recent statements from senior North Korean officials that Pyongyang does not have intentions to talk with Tokyo over the abduction issue despite Japan's diplomatic outreach to secure a meeting between Japanese Prime Minister Fumio Kishida and North Korean leader Kim Jong-un.

"The recent statements from North Korea indicated that they are not ready to deal with those outstanding issues," he said at a forum that the Center for Strategic and International Studies hosted ahead of a summit between President Joe Biden and Kishida set to take place at the White House on Wednesday.

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

Yamada stressed that if North Korea is "forthcoming," Kishida is "ready" to have dialogue with the North.

"We will see how the North Korean side will react," he said.

The ambassador said that Kishida believes a "productive" relationship with the North will be beneficial to both countries as well as for regional stability.

Late last month, North Korean Foreign Minister Choe Son-hui reiterated that her country has no intention to discuss the abduction issue with Japan, as she stressed the North has "nothing to resolve" and has "neither the responsibility nor the will to make any effort for it."

Days before Choe's remarks, Kim Yo-jong, the influential sister of the North Korean leader, also issued a statement, saying the North has "clearly understood" Japan's attitude and will reject any bilateral contact, as Tokyo took issue with the abduction issue.

The issue of Japanese nationals -- abducted by North Korea in the 1970s and 1980s to train spies in Japanese culture and language -- has been an abiding source of tension between the two countries.

Also attending the CSIS forum was US Ambassador to Japan Rahm Emanuel.

Emanuel highlighted the US' pursuit of a "lattice-like" system, which involves America's regional allies for multilateral cooperation to respond to China's increasing assertiveness, in a move away from a "hub-and-spoke" system that focuses on bilateral alliance cooperation.

"When you bring the lattice-like system, it's not to isolate China but to realize their attempt to isolate others either on the economic front, deterrence front, development front does not work," he said.

"The hub-and-spoke system that we built up over the years worked but it's not relevant to this moment. It's a major transformation. The constant in it is the US and Japan," he added. (Yonhap)