There must have been something or someone that tipped off US officials to seize this package because it is pretty serious to take a diplomatic package like this:
North Korea has claimed that the United States recently mugged its delegation carrying a diplomatic package in New York, calling on Washington to provide an explanation on what it calls a provocation.
According to the (North) Korean Central News Agency on Sunday, which quoted its foreign ministry, a group of government officials and police officers from the U.S. took a diplomatic package from its delegation Friday at John F. Kennedy International Airport before it was about to board a flight home.
The delegation was in New York to attend the Conference of States Parties to the Convention on the Rights of Persons with Disabilities, it added.
“As the diplomats vigorously resisted, they grabbed the diplomatic package using physical violence and made off,” the ministry was quoted as saying. It called the incident a “planned and organized provocation.”
The ministry also asked the world to “seriously reconsider” New York as a venue for major international events and demanded Washington provide an explanation for infringing upon its sovereignty.
“If the U.S. fails to give its due response to our demand which is all too reasonable and fair enough, it will be totally responsible for all the consequences to be entailed,” the ministry said. [Yonhap]
You can read more at the link, but it was believed that the North Koreans used a diplomatic package to bring the VX nerve agent into Malaysia to assassinate Kim Jong-nam. I don’t think they would bring something like that to New York, but I would not be surprised if they were taking money out of New York from some criminal enterprise they have going on.