"This launch can possibly be a test for a new type of missile or an upgrade".
The official added that if the USA shows any sign of "reckless" military aggression, Pyongyang is ready to launch a pre-emptive strike of its own.
The comments came as North Korea marked the 105th anniversary of the birth of its founding president, Kim Il-sung.
The arsenal of weapons on display included the new ballistic missile - which is thought to have a range of around 600 miles - and what appeared to be a battery of KN-08 and KN-14 missiles, which analysts believe could reach the USA mainland.
Mr Han Song dismissed the suggestion Trump made past year during his presidential campaign that he was willing to meet Kim Jong Un, possibly over hamburgers.
The North launched a ballistic missile from the same region earlier this month ahead of a summit between the United States and China to discuss the North's arms programme. "If they let war break out on the peninsula, they must shoulder that historical culpability and pay the corresponding price for this".
"They literally could bring North Korea to their knees nearly immediately, by denying electrical power, fuel, by cutting off imports from North Korea", said McCaffrey.
He criticised President Trump for "creating a war situation" on the Korean Peninsula by dispatching strategic military assets to the region.
In an editorial published Saturday after the parade, China's official news agency, Xinhua, said the region was at "a critical moment in history" and a pre-emptive USA strike could trigger full-scale war. If they are unable to do so, the US, with its allies, will! United States of America.
State television showed Kim stepping out of a limousine, wearing black suit and a white shirt, and saluting his honour guard before walking down a red carpet.
"It's in their interest to see North and South Korea reunited in a sensible way, that would end the North Korean nuclear weapons program and in my view that's the only way it's going to happen", he said.
North Korea, still technically at war with the South after their 1950-53 conflict ended in a truce but not a treaty, has on occasion conducted missile or nuclear tests to coincide with big political events and often threatens the United States, South Korea and Japan.
Kim Jong Un, a 30-something leader who took power in late 2011 after the death of his father, Kim Jong Il, emphasizes nuclear weapons as the foundation of his national defense strategy. Experts and government officials believe it is working to develop nuclear-warhead missiles that can reach the US.
North Korea conducted two nuclear tests past year alone, advancing its goal to make nuclear weapons small enough to fit on long-range missiles.
This development comes amidst speculations that the regime was preparing to conduct a nuclear test.
The isolated dictatorship celebrated the 105th birthday of its late founder with a massive military parade displaying what appeared to be previously-unseen KN-08 and KN-14 missiles.
Pulitzer Prize: Presenting the winners
Art Cullen , who owns the Storm Lake Times with his brother John, says his editorials were about government transparency. The Orlando Sentinel won Pulitzers in 1988 and 2000 for editorial writing and in 1993 for investigative reporting .