North Korean leader Kim Jong Un has appeared in a massive parade in the capital.
Leader King Jong Un has used April 15 as a way to fuel patriotism and bolster his own popularity.
Pence's first visit to South Korea - part of an Asia swing that also includes stops in Japan, Indonesia and Australia - was conceived months ago, but could hardly come at a time of higher tension.
Military planes flew in formation, creating the number "105" above Kim Il Sung Square.
"And making it without prompting a furious response from Washington surely qualifies as a win to some degree from Kim's perspective", it said, referring to Kim Jong Un.
The parade also featured the North's submarine-launched ballistic missiles (SLBM) for the first time. Its eventual goal is a long-range nuclear missile that can strike the continental United States.
The show of strength comes amid mounting tension, with a USA aircraft carrier group steaming towards the region. North Korea continues to test and display ICBMs while the US has sent an aircraft carrier strike team to the region and Trump fires off threatening tweets.
"We will respond to an all-out war with an all-out war and a nuclear war with our style of a nuclear attack", Choe said.
North Korea has spent decades trying to develop operational nuclear weapons.
"We urge all parties to refrain from inflammatory or threatening statements or deeds to prevent irreversible damage to the situation on the Korean Peninsula", said Wang Yi, China's foreign minister, according to state news agency Xinhua. "Very powerful", Trump had told the Fox Business Network.
Japan's foreign minister says his country needs to remain on alert over North Korea even after this weekend's celebrations.
Pyongyang has also expressed anger over the ongoing annual spring military exercises the USA holds with South Korea, which it considers a rehearsal for invasion.
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 sacked.
The parade, an elaborate display of the state's vast power, involves tens of thousands of participants, from goose-stepping soldiers to crowds of civilians who have spent weeks perfecting their ability to wave plastic flowers in unison.
The launch, near Shinpo on North Korea's east coast, comes a day after Pyongyang held a military parade to mark the anniversary of the birth of its founder, Kim Il Sung.
In his annual New Year's address, Kim said that the country's preparations for an ICBM launch have "reached the final stage".
"It will be a big game-changer once it is deployed in service but they have got a long testing schedule ahead", he said. -South Korean wargames and the deployment of the aircraft carrier, the USS Carl Vinson, but a tweet Trump posted Tuesday in which he said the North is "looking for trouble".
"The launch of the ballistic missile occurred near Sinpo".
The nuclear-armed North is under United Nations sanctions over its weapons programmes, and has ambitions to build a rocket capable of delivering a warhead to the U.S. mainland -- something Trump has vowed "won't happen". Solid-fuel missiles can be fired more quickly than liquid-fueled missiles because the fuel is already just hanging out in the missile prior to launch.
Also on display, analysts said, were a midrange missile powerful enough to reach US air bases in Guam, and a new solid-fuel midrange missile that could be fired from land mobile launchers, which would also make it hard to detect before it's launched.
Kim Jong Un, a 30-something leader who took power in late 2011 after the death of his father, Kim Jong Il, emphasises nuclear weapons as the foundation of his national defence strategy.
But at the same time, H.R. McMaster said, "it's time for us to undertake all actions we can, short of a military option, to try to resolve this peacefully". North Korea's official name is the Democratic People's Republic of Korea.
South Korean analysts have said that the North might use the parade to showcase its strategic weapons, such as prototype intercontinental ballistic missiles.
Trump has also called for a review of all bilateral trade agreements, including the five year old US-South Korea deal - or KORUS.
As NPR's Merrit Kennedy reported earlier this week, the regime said it would "hold the US wholly accountable for the catastrophic consequences to be entailed by its outrageous actions".