Chinese Foreign Minister Wang Yi says there would be no winners in an armed conflict between the US and North Korea over Pyongyang's nuclear weapons and missile programs.
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 USA, and a looming possibility of the nation's sixth nuclear test. In a test launch in August a year ago, the missile flew 500 kilometers (310 miles) after being launched from a submarine and crashed into waters near Japan, prompting Kim Jong Un to declare that North Korea had gained "perfect nuclear-attack capability".
Earlier this week an aircraft carrier, the USS Carl Vinson, was sent to the area with its strike group, which US President Donald Trump called an "armada".
Kim's close aide Choe Ryong-Hae declared that the North was a "powerful nuclear-armed state in the Orient and Asia's leader in rocketry".
Analysts say commercial satellite images from recent weeks indicate increased activity around North Korea's nuclear test site.
Rows of military bands and goose-stepping and sword-wielding soldiers marched through Pyongyang's main Kim Il-sung square for the "Day of the Sun" celebrations, as a black-suited Kim Jong-un watched on.
Korean People's Army (KPA) tanks are displayed during a military parade marking the 105th anniversary of the birth of late North Korean leader Kim Il-Sung in Pyongyang on April 15, 2017.
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".
The ministry issued a statement saying North Korea will face strong punishment it will find hard to withstand if it makes a significant provocation, such as another nuclear test or an ICBM launch.
"With swords drawn and bows bent, ... there have been storm clouds gathering", China's Xinhua News Agency reported, adding that if North Korea and the USA and its allies "let war break out on the peninsula, they must shoulder the historical culpability and pay the corresponding price for this". Amid rising regional tensions, Pyongyang residents have been preparing for.
North Korean state television showed what appeared to be several KN-08 and KN-14 missiles rolled out on trucks at the parade Saturday celebrating the 105th birthday of Kim Il Sung. USA officials told The Associated Press that the 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.
This year's joint war games between the US and South Korean militaries are the biggest so far.
A US military official, who spoke on anonymity, said the USA doesn't intend to use military force against North Korea in response to either a nuclear test or a missile launch.
North Korea vowed a "merciless" response to any USA provocation.
"That is something that our headquarters decides", Mr Han said of what would be North Korea's sixth nuclear test. South Korea has a spotty record of tracking developments in North Korea, as information about the secretive, authoritarian state is often impossible to confirm. During his New Year's address, Kim said the country's preparations for an ICBM launch had "reached the final stage". It's not two years from now or five years from now.