Japanese Prime Minister Shinzo Abe has reiterated that he needs to sit down with North Korean leader Kim Jong Un for talks so as to secure the return of citizens who were abducted by Pyongyang decades ago.
The stalemate over the issue continues to hang over the two nations, which do not have diplomatic ties.
United States President Donald Trump raised the issue with Mr Kim in Hanoi, Mr Abe said.
"I know that I need to face Chairman Kim myself next," the Japanese Premier added, amid renewed calls by relatives of the abductees for a Japan-North Korea summit.
Mr Abe, who has long taken a hawkish stance on North Korea, told reporters after a 10-minute phone call with Mr Trump that he fully supports the decision not to make concessions easily while at the same time continuing talks to urge North Korea to take concrete steps towards denuclearisation.
Mr Trump and Mr Kim failed to come to an agreement during their second summit on Thursday. The US leader said he walked out because of Pyongyang's demand for economic sanctions to be lifted immediately, though this was refuted by North Korean top envoy Ri Yong Ho in a rare news conference later, who said that the request was for sanctions that affect livelihoods.
Japan, which is within range of North Korea's nuclear arsenal, was concerned prior to the summit that Mr Trump might be tempted to make easy concessions for a quick political win, given domestic pressures. Mr Abe said the two security allies will "continue to cooperate closely towards resolving the abduction, nuclear and missile issues".
The Nikkei newspaper yesterday cited an official close to Mr Abe as saying: "This is better than the US and North Korea making a hasty compromise. North Korea is facing extreme economic difficulties at home due to sanctions."
The report also noted North Korea's propensity of making overtures to Japan when it hits roadblocks in dealing with the US. Japan could leverage this as a chance for an opening.
The Yomiuri daily, whose front-page article was headlined "Back to square one on complete denuclearisation", said in another report that Tokyo intends to seek back channels for talks with Pyongyang, while closely watching developments in US-North Korea talks.
Japanese Foreign Minister Taro Kono, who had said on Thursday that Tokyo will accept nothing less than "complete, verifiable and irreversible denuclearisation", reaffirmed that Japan and the US were on the same page in a 20-minute phone call with Secretary of State Mike Pompeo yesterday.
Japanese media praised Mr Trump's walkout, with the English-language Japan Times saying: "The President was right. No deal is better than a bad deal."
Dr Masashi Nishihara, president of Japan's Research Institute for Peace and Security, told The Straits Times that he saw similarities in Mr Trump's strategy with his abrupt cancellation of the Singapore summit last May, before making a U-turn when Pyongyang extended an olive branch. He said: "I see it as Mr Trump, on purpose, trying to gain the upper hand in negotiations."
Meanwhile, Kobe University security expert Tosh Minohara said it was difficult for him to overlook the small victory that North Korea gained: The continued freeze on US war games with South Korea.
"Holding regular military exercises with a security partner is crucial, and if you don't do it for two years in a row, the operational readiness will be affected," he told The Straits Times.