North Korea’s chief negotiator Kim Myong Gil on Monday warned that a “terrible” event may take place should the U.S. fail to offer Pyongyang a better deal, claiming that the ball is now in Washington’s court to restart dialogue.

Speaking to reporters at Beijing Capital International Airport while en route home from working-level talks with the U.S. over the weekend, Kim reiterated his disappointment with the outcome of the negotiations and said that the Americans had been under-prepared for the meetings.

“The talks were sickening,” Kim was reported to have said