he will listen and get current with leaders in japan and seoul. we have alexandyea alexandria f the latest. reporter: that is why you cannot overstate the significance that james mattis has decided to make south korea the first overseas trip as secretary of defense. it speaks to the seriousness with which the u.s. takes the north korea nuclear threat and under scores the longstanding n alliance with south korea. that alliance which is tight and longstanding was thrown into question when president trump was candidate trump. erahe raised idea of withdrawin some troops from south korea. suggesting south korea should pay more to help with defense. that idea seems to have gone off the table. president trump spoke to the acting president of south korea