North Korea has lobbed another verbal salvo at Washington ahead of an increasingly embattled plan for its leader, Kim Jong Un, and President Donald Trump to meet next month, calling Vice President Mike Pence a “political dummy” and saying it is just as ready to meet in a nuclear confrontation as at the negotiating table. The outburst at Pence, issued in the name of a top Foreign Ministry official, comes on the heels of another sharp rebuke of Trump’s newly appointed national security adviser, John Bolton, and has raised concerns a major gap has opened between the two sides just weeks before the June 12 summit in Singapore. In both cases, Pyongyang was trying to push back against hard-line comments suggesting North Korea may end up like Libya if it doesn’t move forward quickly and irreversibly with concrete measures to get rid of its nuclear weapons.