Which GPA is more important for applying to PhD programs, graduate or undergraduate?

I have BE and MS from the University of Tokyo (a research university in Japan) and I'm planning to study and do research in US as a PhD student.

My questions is: which is more important, GPA at graduate school or GPA at undergraduate school?

I have a GPA of 3.8ish at graduate school and a GPA of 3.4ish at undergraduate school. So this is a very important problem to me.

Please give me a hand! Thank you in advance.