"Though analysts questioned what was inside the missile shells, they said the appearance of a submarine-launched ballistic missile shows North Korea is progressing with its plan to launch missiles from anywhere in the sea".
The failed launch was at 7.21am AEST.
For North Koreans, April 15 is an auspicious date that sees millions celebrate the birth of the nation's founder.
"The launch of the ballistic missile occurred near Sinpo".
"The missile blew up nearly immediately", Benham said. The display featured what appeared to be a new long-range missile and two new types of large missile canisters.
North Koreans offer flowers in front of a mural of late leaders Kim Il Sung, left, and Kim Jong Il on Friday, April 14, 2017, in Pyongyang, North Korea.
Other military hardware at the parade included tanks, multiple rocket launchers and artillery, as well as a solid-fuel missile created to be fired from submarines.
South Korea's military also detected the failed launch. The country said it could test a nuclear weapon whenever its current leader, Kim Jong Un, decided.
Sinpo is on the east coast of North Korea.
"We will respond to an all-out war with an all-out war and a nuclear war with our style of a nuclear attack", said Choe Ryong Hae as translated by the BBC.
During the pomp and circumstance at Kim II Sung square, citizens showed their revolutionary fervor with choreographed performances while vehicles displaying North Korea's military arsenal rolled by.
The parade comes amid rising tensions between North Korea and the rest of the world, after a week-long series of spats directed toward the U.S., and a looming possibility of the nation's sixth nuclear test.
US President Donald Trump's recent bombings in Syria and Afghanistan have stoked fears about a possible US attack on North Korea.
"Trump is always making provocations with his aggressive words", Han Song Ryol told AP in Pyongyang. Yesterday it warned the United States any provocation would be met with retaliation.
Pyongyang has also expressed anger over the ongoing annual spring military exercises the US holds with South Korea, which it considers a rehearsal for invasion. But on Thursday he was hedging his bets: "I have great confidence that China will properly deal with North Korea".
The North has owned up to one such facility, at its Nyongbyon nuclear complex, but the US government assumes it has more.
"We've tried persuasion, it's failed, we've tried coercion, it's failed".
Since taking power in late 2011, Kim Jong Un has executed or purged a slew of high-level government officials in what the South Korean government has described as a "reign of terror". "China is willing to give support to all of them", Wang said.
The official said plans could change in the unlikely event a North Korean missile targets South Korea, Japan or US territory.
North Korea has already conducted five nuclear tests in defiance of UN and unilateral sanctions and experts and military officials believe it is working on developing nuclear warhead missiles that could reach the United States. According to military analysts, these missiles could one day be capable of hitting targets as far as the continental United States. The Washington Post reported that the missile has a theoretical range of 7,500 miles, enough to reach all of the United States.
"It's presumed to be a new ICBM".
The country's biggest national holiday called the "Day of the Sun" came amid growing speculation that Pyongyang could conduct its sixth nuclear test.