The Antarctic Treaty System (ATS) regulates international relations with respect to Antarctica, Earth's only continent without a native human population. The main treaty was opened for signature on December 1, 1959, and officially entered into force on June 23, 1961. As of 2023, there are 56 states party to the treaty, 29 of which, including all 12 original signatories to the treaty, have consultative (voting) status. The consultative members include the 7 countries that claim portions of Antarctica as their territory.