North Korea's attempt to launch a test missile is concerning and UK officials are closely monitoring the situation, the Foreign Office has said.
The US said the launch of a land-based ballistic missile from North Korea's east coast was detected but it had exploded almost immediately.
It comes after the regime warned the US it would not shy away from conflict.
Earlier, UK Foreign Secretary Boris Johnson said Pyongyang must adhere to UN resolutions.
US Vice-President Mike Pence has arrived in South Korea, where he is expected to discuss the best way to deal with North Korea's missile and nuclear programmes.
North Korea has conducted five nuclear tests and a series of missile launches in contravention of UN resolutions in recent years.
On Saturday, it marked the 105th anniversary of the birth of its founding president, Kim Il-sung, with a huge military parade in Pyongyang amid speculation that current leader Kim Jong-un could order a new nuclear test.
The event, which appeared to include new intercontinental and submarine-launched ballistic missiles, was a deliberate show of strength.
The US Pacific Command confirmed the failed test had taken place hours later, with officials saying a missile had exploded within seconds of the launch.
A Foreign Office spokesman said: "We are concerned by reports of a missile test by North Korea and are monitoring the situation closely."
Speaking before the launch attempt, Mr Johnson said: "We have been here before but continue to monitor the situation carefully.
"We stand alongside our international partners in making clear that North Korea must adhere to UN resolutions designed to secure peace and stability in the region and stop its pursuit of nuclear weapons."
Former Conservative Foreign Secretary Sir Malcolm Rifkind said it was possible the missile either malfunctioned or was sabotaged by a US cyber attack.
"It could have failed because the system is not competent enough to make it work, but there is a very strong belief that the US - through cyber methods - has been successful on several occasions in interrupting these sorts of tests and making them fail," he told the BBC.
Sir Malcolm went on: "But don't get too excited by that, they've also had quite a lot of successful tests.
"They are an advanced country when it comes to their nuclear weapons programme. That still remains a fact - a hard fact."
US President Donald Trump has urged China to use its influence with North Korea but said the US is ready to act alone to deal with the nuclear threat.
Ahead of the parade, tension was continuing to rise in the Korean Peninsula with a US aircraft carrier group heading towards the region.
Speaking on Saturday, Liberal Democrat leader Tim Farron said Mr Johnson and Prime Minister Theresa May needed to use what influence they had with Mr Trump to tell him that "aircraft carrier diplomacy is not what the world needs".