SEOUL, South Korea — North Korea on Sunday failed in a missile launch from its eastern coast, South Korea’s Joint Chiefs of Staff said, but it wasn’t immediately clear what kind of missile was fired.

The launch from the city of Sinpo comes a day after one of the biggest North Korean propaganda events of the year — celebrations of the 105th birthday of late North Korea founder Kim Il Sung, the current leader’s grandfather. North Korea regularly launches short-range missiles, but it is also developing mid-range and long-range missiles meant to target U.S. troops in Asia and, eventually, the U.S. mainland.

U.S. Pacific Command said it tracked a missile launched at 5:21 p.m. Eastern Time — a missle that blew up almost immediately, CNN is reporting.

North Korea launched a long-range rocket and conducted two nuclear tests last year, including its most powerful to date. Its eventual goal is a long-range nuclear missile that can strike the continental United States.

Aside from improving the technology, North Korean missile and nuclear tests are seen by outside analysts partly as efforts to bolster the domestic image of leader Kim Jong Un and apply political pressure on Seoul and Washington.

North Korean leader Kim Jong Un is seen in silhouette as he waves during a military parade on Saturday, April 15, 2017, in Pyongyang, North Korea to celebrate the 105th anniversary of the birth of his grandfather, Kim Il Sung, the country’s late founder. | Associated Press

Kim Jong Un has overseen three nuclear tests and a string of missile and rocket launches since taking over after the death of his father, dictator Kim Jong Il, in late 2011.

Another missile test from Sinpo failed earlier this month, when the rocket spun out of control and plunged into the ocean. That launch came shortly before U.S. President Donald Trump’s first meeting with Chinese leader Xi Jinping. China is North Korea’s only major ally.

The extended-range Scud missile in that earlier launch suffered an in-flight failure and fell into the sea off North Korea’s east coast, according to U.S. imagery and assessments.

Despite Sunday’s failure, the North’s previous claim to have used “standardized” warheads has led to worries that it was making headway in its push to develop small and sophisticated warheads to be topped on long-range missiles. The United States, South Korea and other countries have vowed to apply more pressure on the North, but so far nothing has worked to stop Pyongyang’s nuclear program.

North Korea has spent decades trying to develop operational nuclear weapons.

It is thought to have a small arsenal of atomic bombs and an impressive array of short- and medium-range missiles. But it has yet to demonstrate that it can produce nuclear bombs small enough to place on a missile, or missiles that can reliably deliver their bombs to faraway targets.

Soldiers march across Kim Il Sung Square during a military parade on Saturday in Pyongyang, North Korea. | Associated Press

Saturday’s celebratory parade in Pyongyang had featured some of the country’s intercontinental ballistic missiles; Kim Jong Un looked on with delight as his nation flaunted its increasingly sophisticated military hardware amid rising regional tensions.

Kim did not speak during the annual parade, but a top official warned that the North would stand up to any threat posed by the United States.

Choe Ryong Hae said Trump was guilty of “creating a war situation” on the Korean Peninsula by dispatching U.S. forces to the region.

“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, widely seen by analysts as North Korea’s No. 2 official.

The parade, the annual highlight of North Korea’s most important holiday, came amid growing international worries that North Korea may be preparing for its sixth nuclear test or a major missile launch, such as its first flight test of an ICBM capable of reaching U.S. shores.

Missiles are paraded across Kim Il Sung Square during a military parade Saturday in Pyongyang, North Korea. | Associated Press