North Korea warned of a "nuclear showdown" and called US Vice President Mike Pence "ignorant" and "stupid" as it renewed its threat to pull out of a summit with President Donald Trump.
Pyongyang hit out at Mr Pence over remarks he made in an interview with Fox News over concerns North Korea is not committed to denuclearisation ahead of a summit in Singapore on 12 June.
Mr Pence suggested the North may end up like Libya, whose ex-leader Muammar Gaddafi was killed in an uprising years after giving up atomic weapons, "if Kim Jong Un doesn't make a deal" and relinquish its nuclear weapons programme.
He also warned Pyongyang it would be a "mistake" for the North Koreans to think they can "play" Mr Trump ahead of the planned talks.
Choe Son Hui, North Korea's vice-minister of foreign affairs, responded by questioning whether the summit would be worthwhile if Mr Pence's remarks reflected Washington's position.
"Whether the US will meet us at a meeting room or encounter us at nuclear-to-nuclear showdown is entirely dependent upon the decision and behaviour of the United States," she said in a statement to KCNA state news agency.
"We will neither beg the US for dialogue nor take the trouble to persuade them if they do not want to sit together with us."
She added: "In view of the remarks of the US high-ranking politicians who have not yet woken up to this stark reality and compare the DPRK to Libya that met a tragic fate, I come to think that they know too little about us.
"To borrow their words, we can also make the US taste an appalling tragedy it has neither experienced nor even imagined up to now."
Sky News is the only British broadcaster that has been invited to see North Korea's Punggye-ri nuclear site as it is dismantled.
Pyongyang has insisted it will not give up nuclear weapons unilaterally.
Mr Trump said on Tuesday that it was the North that had to meet the conditions for the talks to go ahead.
It is not the first time the US has made the comparison between North Korea and Libya - Mr Trump's security adviser John Bolton and others have suggested Pyongyang should follow the "Libyan model" of nuclear disarmament.
Libya cut its nuclear programme in exchange for the easing of sanctions.
North Korea, however, sees the gruesome death of Mr Gaddafi as justification for its own nuclear development amid what it describes as US threats.