* Japan coastguard, S.Korean military report apparent missile test
* N.Korea's Kim vowed to bolster defense in New Year address
* Repeated N.Korean missile tests 'very regrettable' - Japan PM
SEOUL/TOKYO - North Korea fired a suspected ballistic missile off its east coast on Wednesday, authorities in the region reported, underscoring leader Kim Jong Un's New Year vow to bolster the military to counter an unstable international situation.
Japan's coast guard, which first reported the launch, said it could be a ballistic missile but did not provide further details.
"Since last year, North Korea has repeatedly launched missiles, which is very regrettable," Japanese Prime Minister Fumio Kishida told reporters.
South Korea's Joint Chiefs of Staff also reported that nuclear-armed North Korea fired a presumed ballistic missile from an inland location toward the sea, without elaborating.
"Our military is maintaining readiness posture in preparation for a possible additional launch while closely monitoring the situation in close cooperation with the United States," the JCS said in a statement.
United Nations Security Council resolutions ban all ballistic missile tests by North Korea, and have imposed sanctions over the programs.
In state media summaries of a speech Kim gave ahead of the New Year, the North Korean leader did not specifically mention missiles or nuclear weapons, but said that national defense must be bolstered.
North Korea is under international sanctions over its nuclear weapons program but since the start of the COVID-19 pandemic it has become even more isolated, imposing border lockdowns that have slowed trade to a trickle and choking off any in-person diplomatic engagements.
It has also stuck to a self-imposed moratorium on testing its largest intercontinental ballistic missiles (ICBMs) or nuclear weapons. The last tests of ICBMs or a nuclear bomb were in 2017, before Kim launched a diplomatic overture to the United States and South Korea that has since stalled.
But the country has continued test firing new, short-range ballistic missiles, including one launched from a submarine in October.
"While the readout from North Korea’s recent plenary meetings may have prioritized rural development for the coming year, it doesn’t mean the country will halt its ballistic missile tests," said Michelle Kae, deputy director of 38 North, a North Korea monitoring program at Washington’s Stimson Center.
For the first time in his 10 years of rule, Kim did not publicly appear at any missile tests or military drills last year, according to an analysis by NK News, a Seoul-based website that monitors North Korea. Health issues or efforts to minimize attention may have played a role in his official absences, the site said.
The White House, Pentagon and U.S. State Department did not immediately respond to requests for comment on Wednesday's launch.
At a regular news briefing on Monday, State Department spokesperson Ned Price reiterated the U.S. desire for dialogue with North Korea aimed at increasing the security of the United States and its allies in the region. He repeated that Washington had no hostile intent towards North Korea and was prepared to meet without preconditions.
Price declined to comment on Kim’s slimmer appearance in a photo published recently in North Korean state media and on speculation about his health, saying "we don’t want to add to that speculation."
Kim's latest speech made no mention of efforts by South Korea to restart stalled negotiations or offers by the United States to talk without preconditions, casting doubts on South Korean President Moon Jae-in's push to achieve a breakthrough before he term ends in May.
North Korea continues to advance its nuclear weapons and missile programs despite United Nations Security Council sanctions and high-level diplomatic efforts, the U.S. government's Congressional Research Service concluded in a report last month.
"Recent ballistic missile tests and military parades suggest that North Korea is continuing to build a nuclear warfighting capability designed to evade regional ballistic missile defenses," the report said. (Reporting by Chang-Ran Kim in Tokyo, Hyonhee Shin in Seoul, and David Brunnstrom in Washington; Writing by Josh Smith; Editing by Stephen Coates and Lincoln Feast.)