The State Department on Tuesday reiterated the United States' goal to achieve the "full" denuclearization of the Korean Peninsula, after North Korea signaled openness to improving ties with Japan as long as Tokyo does not take issue with its "right to self-defense."

Last week, Kim Yo-jong, the sister of North Korean leader Kim Jong-un, said that Japanese Prime Minister Fumio Kishida might be able to visit Pyongyang if Tokyo "drops its bad habit" of taking issue with its right to self-defense and the issue of Japanese abducted decades ago.

Kim's mention of the right to self-defense was construed as the North's refusal to abandon its nuclear weapons program.

"I think that's a pretty big if. I think I will wait to see how the government of Japan responds to that question before I weigh in any further," Matthew Miller, the department's spokesperson, told a press briefing.

He was responding to a question over what impact the South Korea-US alliance will bear if Japan embraces the North's preconditions for Kishida's visit to Pyongyang and holds talks with the recalcitrant regime.

"I am aware of the North Korean offer. I have not seen the government of Japan respond, but it will continue to be our policy to achieve the full denuclearization of the Korean Peninsula," he said.

In a separate briefing, Pentagon's deputy spokesperson Sabrina Singh said that the United States supports diplomatic outreach to North Korea.

"We have also said from here that we would seek diplomatic outreach should they want to engage," she said. "We want to see regional stability in the region. If those conversations lead to that, we certainly welcome that."

The North's show of interest in high-level diplomacy with Japan has raised questions over whether its move would cause any fissure in ongoing efforts to strengthen trilateral security cooperation among Seoul, Washington and Tokyo to counter growing North Korean threats. (Yonhap)