The Swiss government says the Palestinians can join the Geneva Conventions, the international rules of war that also cover occupations.
The Palestinians signed letters of accession to several international conventions after Israel failed to carry out a planned prisoner release after the end of a March deadline. On Thursday, the United Nations said Secretary-General Ban Ki-moon accepted Palestinian applications to join 13 other conventions.
Switzerland's Foreign Ministry, as the depositary of the Geneva Conventions, said Friday that "the state of Palestine" acceded to the conventions effective April 2.
Israel argues that the Geneva Conventions forbidding colonization of occupied land shouldn't apply to the West Bank and Gaza because it is not universally accepted as a state in its own right.