Japanese Prime Minister Shinzo Abe said on Friday he was determined to meet North Korea's leader to resolve the issue of Japanese nationals abducted by North Korean agents, maintaining an offer to talk despite the country's missile launches.

North Korea said this week it had successfully test-fired a new submarine-launched ballistic missile from the sea, to contain external threats and bolster self-defence, ahead of fresh nuclear talks with the United States.

"I am determined to meet with Chairman Kim Jong Un face-to-face, with no preconditions, to resolve the all-important abduction issue," Abe said in a policy speech at the beginning of a parliamentary session.

In 2002, North Korea admitted its agents had kidnapped 13 Japanese decades before. Japan says 17 of its citizens were abducted, five of whom were repatriated. North Korea has said eight are dead and another four never entered the country.

Abe has vowed to pursue the issue until all the abductees come home, despite regional tension over the North's nuclear and missile programmes.

Staunch US ally Japan and North Korea have been rivals for decades. During periods of tension, North Korea has threatened to rain destruction down on Japan, and North Korea has test-fired missiles into the seas near Japan and even over it.

"The abductees issue is core to Abe's political identity and one of the reasons he's got to the position he has," said Jeff Kingston, director of Asian studies at Temple University's Japan campus.

But Abe has little leverage over Pyongyang at a time when US President Donald Trump is pursuing further talks with the North Korean leader. The two sides are set to hold fresh nuclear talks on October 5.

"The only role Japan will play is to bankroll whatever deal is struck," said Brad Glosserman, deputy director of the Center for Rule-making Strategies at Tama University in Tokyo.

"In the interim, North Korea has no reason to speak to Japan and will use it as a scapegoat to pull out whenever they want."

Japan condemned North Korea's latest missile test on Wednesday, with Abe saying it was a violation of United Nations sanctions.

The launch was the North's most provocative since it resumed dialogue with the US in 2018 and a reminder from Pyongyang of the weapons capability it has been aggressively developing.

"As for the North Korean situation, we will do our utmost to secure the safety of the people, while working closely with the United States and cooperating with the international community," Abe said in his speech.

Turning to ties with South Korea, soured by a feud over wartime labour that has spilled over into trade and security matters, Abe reiterated a call for Seoul to observe a promise to Tokyo.

Last October, South Korea's Supreme Court ordered some Japanese firms to compensate Koreans forced to work in their mines and factories during World War Two.

Japan, which says the matter was settled by a 1965 treaty, calls the court decision a violation of international law.

"South Korea is an important neighbour. I would like to ask them to observe a promise made between nations, based on international law."