UNITED NATIONS — The Palestinians submitted documents to the United Nations to join the International Criminal Court on Friday, a high-stakes move that will soon enable them to pursue war-crimes charges against Israel.

The Palestinians moved quickly to join the court after suffering a defeat in the U.N. Security Council, which rejected a resolution Tuesday that would have set a three-year deadline for the establishment of a Palestinian state on lands occupied by Israel.

Handing over the paperwork is the last formal step for Palestine to become a member of the world's permanent war crimes tribunal.

"This is a very significant step," Palestinian Ambassador Riyad Mansour told reporters after delivering the documents to the U.N. assistant secretary-general for legal affairs. "It is an option that we are seeking in order to seek justice for all the victims that have been killed by Israel, the occupying power."

Israel has threatened retaliation if the Palestinians join the court, and the United States has also vehemently opposed the move as an obstacle to hopes of reaching an Israeli-Palestinians peace deal.

Palestinian President Mahmoud, under heavy pressure to take stronger action against Israel after a 50-day war with between the Jewish state and militants in Gaza over the summer, signed the documents a day after the Security Council rejected the resolution.

Mansour said the Palestinians are seeking to raise alleged crimes previously committed by Israel, including those that occurred during last summer's war in Gaza. He said the Palestinians will also be seeking justice for Israeli settlements on Palestinian territory, which he said constitute "a war crime" under the Rome statute that established the court.

The Palestinians could seek to have Israeli military or political figures prosecuted for alleged crimes involving settlement construction on occupied lands or actions by the military that cause heavy civilian casualties.

Mansour said the Palestinians delivered a letter Thursday night to the registrar of the ICC in The Hague requesting that the court consider alleged crimes committed during the Gaza war "and reserving our right for other retroactive crimes committed by Israel." He said he would be meeting with an official from the registrar's office in New York later Friday to discuss the issue.

It became possible for the Palestinians to join the International Criminal Court after the U.N. General Assembly voted overwhelmingly in November 2012 to upgrade the Palestinians' status from a U.N. observer to a non-voting observer state.

Last month, the 122 members of the Assembly of States Parties to the Rome Statute, which established the ICC, decided to allow the Palestinians to participate in their meeting at U.N. headquarters as an observer state.

Mansour said it will take about 60 days under ICC rules for "the state of Palestine" to become the 123rd member of the court.