The British government took possession of the territory in 1923 and entrusted it to the administration of New Zealand. Under the provisions of the Antarctic Treaty System, to which New Zealand is a signatory, no nation may make efforts to enforce sovereignty or territorial claims over the Antarctic continent proper. If one accepts the claim, the Ross Dependency comprises the bulk of the territory of New Zealand, far larger than the North Island and the South Island combined. However, the actual amount of land mass claimed is not large; most of the area defined as being in the Ross Dependency is either in the Ross Sea or the Antarctic Ocean. It is the smallest of the claims which were made prior to the implementation of the Antarctic Treaty System and the suspension of all territorial claims to Antarctica proper.