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.
Han dismissed the suggestion Trump made previous year during his presidential campaign that he was willing to meet Kim Jong Un, possibly over hamburgers.
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.
Following repeated missile tests that drew global criticism, China banned all imports of North Korean coal on 26 February, cutting off the country's most important export product.
Other military hardware at the parade included tanks, multiple rocket launchers and artillery guns, as well as a solid-fuel missile created to be fired from submarines.
"Our toughest counteraction against the USA and its vassal forces will be taken in such a merciless manner as not to allow the aggressors to survive".
North Korea has conducted a raft of missile and nuclear tests in defiance of United Nations and unilateral sanctions, and there is anxiety it might stage a sixth nuclear test on Saturday to coincide with the "Day of the Sun'", the 105th anniversary of the birth of state founder Dear Leader Kim Il-sung.
Russian ambassador to North Korea Alexander Matsegora said Pyongyang could carry out new ballistic missile launches or conduct nuclear tests in the near future, expressing concern that Trump could take a fateful decision without any North Korea experts on his team.
North Korea has not made secret its desire to boost its military power, while a USA naval strike group is now heading to waters off the Korean Peninsula in a show of force, following high-profile US military attacks this month on Syria and the Islamic State in a remote part of Afghanistan.
The Institute for Science and International Security cited a worrying increase in North Korea's nuclear program, but said the arsenal may only have been as large as 13 atomic weapons at the end of 2016.
In his annual New Year's address, Kim said that the country's preparations for an ICBM launch have "reached the final stage".
Satellite imagery suggests North Korea could conduct another underground nuclear test at any time.
They were taken to what officials billed as a "big and important event" early on Thursday which turned out to be the opening of a new street in the centre of the capital, attended by current leader Kim Jong Un.
Led by rows of military bands, columns of troops toting rifles and a troupe of sword-wielding female soldiers marched into the vast square in the heart of the city which was festooned in the national colours of blue, white and red.
With an American naval carrier looming near the peninsula, and North Korea all but promising another nuclear test, China has urged both countries to stop provoking each other.
China is no doubt burning up the wires today, pleading with Kim not to test a nuclear weapon.