Tensions have spiked amid fears in the West that North Korea is preparing for another round of nuclear or missile tests.
"All the brigandish provocative moves of the U.S.in the political, economic and military fields pursuant to its hostile policy toward the DPRK will thoroughly be foiled through the toughest counteraction of the army and people of the DPRK", North Korea's KCNA news agency said, citing a spokesman for the General Staff of the Korean People's Army. North Korean leader Kim Jong Un has appeared i. Experts have speculated the annual celebration of the founder's birthday might be an occasion for North Korea to conduct a missile test - or even its sixth nuclear weapons test. Friday, a top aide to Kim Jong Un accused President Trump of pushing the world toward nuclear war.
State television showed what appeared to be several KN-08 and KN-14 missiles rolled out on trucks at the parade.
North Korea's state television showed thousands of soldiers marching at Kim Il Sung Square on Saturday to kick off the event that is expected to be attended by leader Kim Jong Un.
North Korea's Pukkuksong submarine-launched ballistic missiles (SLBM) were also on parade.
"I say this because Trump tweeted that the DPRK, North Korea, is looking for trouble and it's none other than the U.S. that is posing threats toward the DPRK with the largest scale ever military exercises (with South Korea) and the nuclear aircraft carrier Carl Vinson which was bound for Australia is now coming back to the Korean Peninsula".
After a 21-gun salute, tens of thousands of soldiers, sailors and airmen goose-stepped through Kim Il-Sung Square turning their eyes towards the high balcony from where Kim watched, flanked by officers and officials.
Analysts say commercial satellite images from recent weeks indicate increased activity around North Korea's nuclear test site.
After dispatching the aircraft carrier USS Carl Vinson and an accompanying battle group to the Korean peninsula Trump told the Fox Business Network: "We are sending an armada".
North Korea is working to develop a nuclear missile that can strike the United States.
But U.S. officials told The Associated Press on Friday that the Trump administration had settled on a policy that will emphasize increasing pressure on Pyongyang with the help of China, North Korea's only major ally, instead of military options or trying to overthrow Kim's regime.
North Korea is technically still at war with South Korea and its ally the US, since the Korean War ended in a truce instead of a peace treaty. Cold launches would also allow the missiles to be fired from silos.
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.
Kim, a 30-something leader who took power in late 2011, emphasizes nuclear weapons as the foundation of his national defense strategy.
Other senior officials joining Kim at the parade podium included Kim Won Hong, who the South Korean government had said earlier this year was sacked from his job as state security minister, presumably over corruption. US satellite imagery suggests the country could conduct another underground nuclear test at any time. South Korea has a spotty record of tracking developments in North Korea, as information about the secretive, authoritarian state is often impossible to confirm. These missiles concern South Korea because they're harder to detect before launch than liquid-fuel missiles, which need to be filled with fuel before launch and also require fuel trucks and other vehicles that could be spotted by satellites.