That raised questions about Trump's plans for North Korea, which has conducted missile and nuclear tests in defiance of United Nations and unilateral sanctions.
"I have great confidence that China will properly deal with North Korea", he tweeted."If they are unable to do so, the US, with its allies, will!" North Korean leader Kim Jong Un has appeared i.
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.
North Korean state media warned that such "reckless acts of aggression" would be countered with "whatever methods the USA wants to take".
Fears over the North's rogue weapons programme have soared in recent days, with a U.S. naval strike force deployed near the Korean peninsula, while President Donald Trump has warned the threat "will be taken care of" and Pyongyang has vowed a "merciless" response to any provocation.
Prototype intercontinental ballistic missiles have highlighted a broad range of military hardware North Korea displayed in a massive parade honoring the country's late founding father.
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.
It could "beat down enemies with the power of nuclear justice", he said, and was "prepared to respond to an all-out war with an all-out war".
North Korea says it's created a nuclear weapon small enough to mount on a missile, though many experts dispute that claim.
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.
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North Korean soldiers also rolled out what appeared to be another large rocket covered by a canister.
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.
Choe Ryong Hae, a close aide to Kim Jong Un, made a speech at the parade, saying the country is ready to stand up to any threat posed by the United States.
Mr Trump also flexed his military muscle last week by ordering cruise missile strikes on a Syrian air base.
Weapons analysts said they believed some of the missiles on display were new types of intercontinental ballistic missiles (ICBM).
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.
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 USA mainland -- something Trump has vowed "won't happen".
In his annual New Year's address, Kim said that the country's preparations for an ICBM launch have "reached the final stage".
An official from South Korea's Unification Ministry, who spoke on condition of anonymity, citing office rules, confirmed that the man was Kim Won Hong and said his appearance shows he has been reinstated from a "purge state". Recent satellite imagery suggests the country could conduct another underground nuclear test at any time. 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.