North Korea's top negotiator in just-resumed nuclear talks with the United States warned Monday of "terrible events" unless the United States comes to the negotiating table well prepared.

Kim Myong Gil made the remark at Beijing airport on his way back to North Korea from Sweden, where he had announced that the U.S.-North Korea working-level denuclearization talks that had restarted after months of stalemate "broke off" after just one day.

"If the United States is not well prepared, we don't know what terrible events will happen," Kim told reporters at the airport. He said that whether the talks continue hinges on the United States. North Korea said Sunday there was no way the United States would bring alternative plans for their stalled nuclear talks to a meeting proposed by Stockholm in two weeks after the negotiations broke down.