government would continue its quote maximum pressure campaign to isolate north korea. some of his former colleagues, other veteran diplomats are lamenting. saying yun was one of the best of the best and vast experience in asia and north korea. last year, he had the delicate and tragic assignment of going to pyongyang to retrieve the university student otto warmbier who essentially was dying in a coma. the loss of the man at a time when diplomacy is so important because the stakes are so high on the korean peninsula is something again that some colleagues are la mementing sti to this day because there is no u.s. ambassador here in seoul. >> suggesting he is retiring because of the issues on policy? >> reporter: again, he stressed