interest rates in the US vs NZ

[Trudy B.]

Just want some clarification about interest rates in the US.  Say for example when people post they have a conventional 30 year fixed loan @ 5% with 20% down, am I right in assuming that the interest rate will be fixed at 5% for the whole 30 years?    Just wondering as in New Zealand we can get 30 year loans but the majority of lenders will only fix the interest rate for maximum of 5 years.  

Many thanks 

Trudy