You Do Need power plug adapter while traveling from Malta to American Samoa.

Here is Why You Need An Adapter

The outlet and plug type used in American Samoa are A, B, F and I and in Malta is G. This is how they look like.

Malta

In Malta, outlets of type G are in use.

Type G

American Samoa

In American Samoa, outlets of type A, B, F and I are in use.

Type A

Type B

Type F

Type I