North Korea’s chief negotiator has issued a fierce statement calling the South Korean government “ignorant and incompetent,” and threatening to halt all talks with the South unless its demands are met. Ri Son Gwon, chairman of North Korea’s Committee for the Peaceful Reunification of the country, issued the latest in a string of inflammatory statements Thursday, in a marked change from the warm words between the countries over the past months. “Unless the serious situation which led to the suspension of the north-south high-level talks is settled, it will never be easy to sit face to face again with the present regime of South Korea,” he said. South Korea earlier offered to act as a “mediator” to smooth out the differences between the U.S. and North Korea. A South Korean official said Thursday the country will “sufficiently convey [to the United States] what we’ve discerned about North Korea’s position and attitude... and sufficiently convey the United States’ position to North Korea” to help ensure the talks do go ahead.