You Do Need power plug adapter while traveling from Argentina to Kiribati.

Here is Why You Need An Adapter

The outlet and plug type used in Kiribati is I and in Argentina are C and I. This is how they look like.

Argentina

In Argentina, outlets of type C and I are in use.

Type C

Type I

Kiribati

In Kiribati, outlets of type I are in use.

Type I