Kim Jong-un's military is expected to carry out an intercontinental ballistic missiles drill amid the festivities, as part of a display of military might for countries overseas to witness.
"It's presumed to be a new ICBM".
North Korean school children perform at the Mangyongdae Children's Palace in Pyongyang while an image of their late leader Kim Il-sung is projected on a screen Friday, April 14, 2017. Amid rising regional tensions, Pyongyang residents have been preparing for North Korea's most important.
He said: "If the USA comes with reckless military manoeuvres then we will confront it with a pre-emptive strike". It staged a similar lavish parade in 2012 to mark the centenary of Kim Il-sung's birth.
North Korea conducted two of such tests past year alone, which analysts say would have taken the country a step forward in gaining the knowledge to make nuclear weapons small enough to fit on long-range missiles.
"We're prepared to respond to an all-out war with an all-out war and we are ready to hit back with nuclear attacks of our own style against any nuclear attacks", Choe Ryong-Hae said in a speech at a ceremony before a large military parade started, which was broadcast live by the North's Korean Central TV. "It can be official or unofficial, through one channel or dual channels, bilateral or multilateral", he said.
North Korea's army on Friday vowed a "merciless" response to any U.S. provocation, as tensions soar over Pyongyang's nuclear programme and speculation mounts that it is preparing a fresh weapons test.
Trump has repeatedly said he will prevent Pyongyang from its goal of developing a nuclear-tipped ballistic missile capable of reaching the mainland United States. US satellite imagery suggests the country could conduct another underground nuclear test at any time.
The North also showed off various other ballistic missiles including what it claims to be a submarine-launched ballistic missile (SLBM).
North Korea threatened merciless consequences to US provocations on Friday, while China warned the two countries to avoid continuing talk of military conflict.
As North Korea marks its founders day, it warned to face retaliation to any kind of U.S. military attack.
Amid the elevated tensions, the United States a few days ago dispatched what Trump called an "armada" of ships in a show of force, including an aircraft carrier, into waters off the Korean Peninsula.
Pyongyang has expressed anger over the annual spring military exercises the US holds with South Korea, which it considers an invasion rehearsal.
North Korea, still technically at war with the South after their 1950-53 conflict ended in a truce but not a treaty, has on occasion conducted missile or nuclear tests to coincide with big political events and often threatens the United States, South Korea and Japan.
Pyongyang's rogue atomic ambitions have come into sharp focus in recent weeks, with United States President Donald Trump vowing a tough stance against the North and threatening unilateral action if China failed to help curb its neighbour's nuclear programme.