operations and the deputy national security adviser planning for the event. the possibility of the historic meeting with trump and kim jong-un. dave and christine. >> we will see what happens, i guess, as trump says. ivan, thank you. u.s. government employees in china on alert after one official experienced a range of abnormal symptoms. it appears the symptoms were similar to those which occurred in cuba recently. top diplomats involved. we have cnn's matt rivers with the latest. what happened to this american and what is the state department saying about it? >> reporter: we know so far and within the last hour or so, china said it conducted its own investigation into what happened. preliminarily saying they have no leads or causes. let's update the viewers on what caused this. yesterday afternoon in china that the u.s. embassy sent a