Japanese Prime Minister Shinzo Abe condemned the launch of what he said were two ballistic missiles, one of which fell in the waters of Japan's Exclusive Economic Zone (EEZ), saying it was a violation of United Nations Security Council resolutions.

The launch was likely a reminder by the North, which rejects the UN resolutions banning the use of ballistic missile technology as an infringement on its right to self-defence, of its weapons capability ahead of the talks with Washington, analysts said.

Talks aimed at dismantling North Korea's nuclear and missile programs have been stalled since a second summit between US President Donald Trump and North Korean leader Kim Jong-un in Vietnam in February ended without a deal.

South Korea's military said it had detected the launch of one missile that flew 450km and reached an altitude of 910km.

It was likely a Pukguksong-class weapon, as the North's earlier submarine-launched ballistic missiles (SLBM) were known, that is under development.

The National Security Council in Seoul expressed "strong concern" over the launch of what it said may have been an SLBM, according to a statement issued by the presidential Blue House, that came just a day after the announcement of working-level nuclear talks.

South Korea's military said the missile was launched from around Wonsan, the site of one of North Korea's military bases on the east coast, towards the sea. There was no immediate explanation for the discrepancy with Japan's assessment that two missiles had been fired.

North Korea had been developing SLBM technology before it suspended long-range missile and nuclear tests and began talks with the United States that led to the first summit between Kim and Trump in Singapore in June 2018.

Japan's Chief Cabinet Secretary Yoshihide Suga said it appeared two missiles were launched within minutes of each other and that the second fell in Japan's EEZ at 7.27am on Wednesday.

The latest launch was the ninth since Trump and Kim met at the Demilitarised Zone border between the two Koreas in June and pledged to reopen working-level talks within weeks.

Hours before Wednesday's launch, North Korean Vice Foreign Minister Choe Son Hui said in a statement the talks would be held on Saturday in a development that could potentially break what had been months of stalemate.

"It seems North Korea wants to make its negotiating position quite clear before talks even begin," said Harry Kazianis, senior director of Korean studies from the Centre for the National Interest.

Trump has played down North Korea's recent series of short-range launches, saying in September the United States and North Korea "didn't have an agreement on short-range missiles" and that many countries test such weapons.

Australian Associated Press