The Palestinians formally presented a request to the United Nations on Friday to join the International Criminal Court, a move that would allow war crimes complaints to be filed against Israel.
Membership of the Rome Statute, which governs the ICC, would open the way for Palestinians to pursue criminal complaints in The Hague, but is firmly opposed by Israel and the United States.
"This is a very significant step," Palestinian envoy Riyad Mansour told reporters.
"We are seeking justice for all the victims that have been killed by Israel, the occupying power."
Secretary General Ban Ki-moon is to review the so-called instruments of accession and notify state members on the request within 60 days.
"We are honored that we are the 123rd state-party of the ICC, which will be effective in about 60 days from now in accordance with the rules and procedures of the ICC," Mansour said.
Palestinian leader Mahmud Abbas signed requests to join the ICC and 16 other conventions on Wednesday, a day after the Security Council failed to adopt a resolution paving the way to full statehood.
The move is part of a shift in strategy for the Palestinians, who are seeking to internationalize their campaign for statehood and move away from the US-led negotiation process.
The United States has branded the move to seek ICC membership as "counterproductive" and warned it would only push the sides further apart.
But the Palestinians hope joining the court will allow them to seek justice against Israel for its actions in the occupied territories.
The Palestinian envoy submitted the documents to the United Nations' top legal affairs official, Stephen Mathias, at UN headquarters in New York.
- ICC to look at Gaza war, settlements -
Mansour said the Palestinians had also filed a request with the ICC in The Hague to grant retroactive jurisdiction to the court to cover alleged war crimes committed during last year's Gaza war.
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Almost 2,200 Palestinians were killed in July and August during the 50-day war in Gaza, including more than 400 children, according to UN estimates.
Mansour said the Palestinians will also be seeking to launch legal action over Jewish settlement construction, which he said was a war crime under the Rome Statute.
"This is a peaceful option, a civilized option and an option that anyone who upholds the law should not be afraid of," he said.
The Palestinians were upgraded from observer entity to a UN "observer state" in 2012, opening the possibility for them to join the ICC and a host of other international organizations.
Israel is not a party to the Rome Statute and does not recognize the court's jurisdiction.
Human Rights Watch legal affairs counsel Balkees Jarrah said Ban was expected to certify that the Palestinian documents are in order and that the state of Palestine can join the Rome Statute.
"The assumption is that he will accept the instruments," said Jarrah.
Ban could turn to the UN General Assembly for guidance, but given that it was the 193-nation body that upgraded the Palestinian status at the UN, joining the ICC would be considered a logical step following that decision, Jarrah said.
- Palestinians weigh options -
Despite the setback at the Security Council, the Palestinians have said they will be looking at other measures at the General Assembly and other UN venues to press for recognition.
"We are studying all of our options and we will be mapping our course accordingly," envoy Mansour said.
China, France and Russia were among eight countries that backed the resolution on ending the Israeli occupation by the end of 2017, but the result fell short of the nine votes required for adoption.
The United States and Australia voted against and five other countries abstained, among them Nigeria, which had been expected to vote in favor but changed its stance at the last minute.
The Palestinians are considering further action at the Security Council, which started the year with five new countries seen as having a more pro-Palestinian stance, Mansour said.