The defence relations between Chile and Argentina are generally positive and cooperative. Both countries are members of the Union of South American Nations (UNASUR) and have taken part in joint military exercises and peacekeeping missions.

They also have a mutual defence agreement, which allows for cooperation in military and security matters. Furthermore, both countries have worked to improve their defence cooperation in recent years.

They hold joint military exercises to improve interoperability and strengthen their defence relationship. Over the next 12 months, this cooperation is likely to continue.