North Korea says won't hold talks with 'incompetent' South unless differences settled

South Korean President Moon Jae-in talks on the phone to Chinese President Xi Jinping at the Presidential Blue House in Seoul, South Korea, May 4, 2018. Yonhap via REUTERS

SEOUL (Reuters) - North Korea's chief negotiator called the South Korean government "ignorant and incompetent" on Thursday, denounced U.S.-South Korean air combat drills and threatened to halt all talks with the South unless its demands are met.

The comments by Ri Son Gwon, chairman of North Korea's Committee for the Peaceful Reunification of the country, were the latest in a string of inflammatory statements marking a drastic change in tone after months of easing tension with plans for denuclearisation and a summit scheduled with the United States.