them. even for the u.s. state department, credible information is difficult to obtain from one of the world s most see creative nations. we ve seen the reporting which you ve referred and doing our best to check it out. reporter: as for secretary of state mike pompeo s negotiating parter kim yong chol who hand delivered a letter to president trump in the oval office, the same south korean paper says he s been dismissed and is doing forced labor. the paper says kim s interpreter in hanoi is in prison in a political camp for a critical interpretation error. kim s trusted younger sister, kim yo-jong may have been affected, the paper says. she s reportedly been removed from official activity. i see it as him feeling that he was going to come through with an agreement with president trump in hanoi and he s trying to blame somebody. reporter: the breakdown in talks in hanoi led to escalating
kim jong-un and his delegation smiled politely when president donald trump walked out of february s failed summit in vietnam but south korea s largest newspaper says kim is believed to be carrying out a purge of top officials following the epic failure of negotiations with the trump administration. cho sun ill bo says special envoy to the u.s., kim yong chol was executed in march for betraying the supreme leader. we re aware of reports that there has been an execution but since we do not have any way of confirming that i wouldn t have further comment. reporter: cnn has checked with numerous sources and is not able to verify the newspaper s reporting. south korean reports said north korean executions have at times been inaccurate. a senior diplomatic source with knowledge of the situation tells cnn these top officials have certainly disappeared, but there s no independent information or intelligence at this point on what s happened to