Referring to Kim Jong-un's earlier remarks that the country will take the "highest-level", an official in the rogue nation said this could be dropping an H-Bomb in the sea.
Foreign Minister Ri Yong-ho made the comment after Kim said he will have the strongest possible response to US President Donald Trump's threat to "totally destroy" the country.
Ri said: "It could be the most powerful detonation of an H-bomb in the Pacific.
"We have no idea about what actions could be taken as it will be ordered by leader Kim Jong-un."
Ri is currently in New York to attend the UN General Assembly.
It comes just weeks after North Korea carried out its sixth and largest nuclear test to date with what it said was a hydrogen bomb.
Kim delivered a fiery response to Trump's UN address, calling the President "deranged".
He said: "I am now thinking hard about what response he could have expected when he allowed such eccentric words to trip off his tongue.
"Whatever Trump might have expected, he will face results beyond his expectation.