Section 51(xxix) of the Constitution of Australia

Section 51(xxix) of the Australian Constitution is a subsection of Section 51 of the Australian Constitution that gives the Commonwealth Parliament of Australia the right to legislate with respect to "external affairs". In recent years, most attention has focused on the use of the power to pass legislation giving effect within Australia to its obligations under international treaties and conventions.

Source: Wikipedia — Section 51(xxix) of the Constitution of Australia (CC BY-SA 4.0)