Setback comes amid concern Pyongyang, which has carried out a series of tests this year, plans to launch a banned ICBM.
North Korea’s neighbours have said the nuclear-armed country fired an “unidentified projectile”, but the launch appears to have failed.
“North Korea fired an unknown projectile around 09:30 (00:30 GMT) today, but it is presumed that it failed immediately after launch,” Seoul’s Joint Chiefs of Staff said in a statement. The suspected missile was fired from an airfield outside the North Korean capital of Pyongyang, it added.
Japanese media earlier reported that the North had fired a possible ballistic missile, citing an unnamed defence ministry official.
Pyongyang has carried out a record nine weapons tests so far this year – the most recent on March 5.
The North has said two of the launches were a “reconnaissance satellite”, but South Korea and the United States have said they believe those tests were related to a new intercontinental ballistic missile (ICBM) system – a so-called “monster missile” that has never been test-fired before.
Officials in Seoul and Washington have also said that the North appears to be restoring some of the tunnels at Punggye-ri, the site where it conducted six nuclear weapons tests between 2006 and 2017.
The site was closed in 2018 when Pyongyang declared a moratorium on nuclear testing ahead of a series of summits with South Korean President Moon Jae-in, and then US President Donald Trump.
That diplomacy failed to make any headway and talks on denuclearisation have been stalled since the Trump-Kim summit in Hanoi in 2019 collapsed over the issue of sanctions relief.
In January, a meeting of the powerful politburo of North Korea’s ruling party presided over by leader Kim Jong Un, said it would consider resuming “all temporarily suspended” nuclear and ICBM tests as part of an effort to boost the country’s military against a “hostile” United States.
North Korea is under stringent international sanctions over its missile and nuclear weapons programme and is banned from testing ballistic missiles by the United Nations.
The US has imposed more sanctions as a result of this year’s tests.