US Secretary of State Mike Pompeo resumed talks in New York on Thursday with a top North Korean official as the pair work to salvage next month's nuclear summit between Donald Trump and Kim Jong Un, an AFP journalist on the scene said.

Kim Yong Chol, considered the North Korean leader's right-hand man, is the most senior official from Pyongyang to visit the United States in 18 years.

He and Pompeo shook hands shortly after 9:00 am (1300 GMT) and began their talks over breakfast, with four people on each side.