The letter condemned the killing of Ecuadorian volunteer Carlos Andres Chavez by a Palestinian sniper at Kibbutz Ein Hashlosa in southern Israel and the Qassam attack on Sderot, which included more than 40 rockets and lightly injured four people.
Israel called on the United Nations to condemn the incidents and the states which are members of the UN while aiding terror organizations.
Ambassador Danny Carmon, the deputy head of the Israeli delegation to the UN, said in the letter that while Israel remained committed to advancing the peace process and the understandings of the Annapolis peace conference, the Palestinian Authority did not meet its obligations.
According to the letter, following Israel's withdrawal from the Gaza Strip, the Jewish state expected the PA to control Gaza and prevent terror attacks. However, since Hamas took over the Strip in June 2007, more than 1,000 Qassam rockets and mortar shells were launched from the Strip towards Israel.
Israel is entitled to defend itself against a military offensive like any other country under Article 51 of the UN Charter, the letter said, adding that the Israeli delegation is constantly pressuring the UN to condemn all terror attacks and condemn countries helping terror organizations and violating their commitments according to international law.
According to the letter, which is also aimed at preparing the ground for the possibility of a wide-scale Israeli military operation in the Gaza Strip, violence continues and nothing is being done to halt terrorism or the support for it.
The Israeli delegation to the UN has recently been filing a complaint following every terror attack or rockets fired at Israel.
Last week, a harsh complaint was submitted following the firing of two Katyusha rockets from Lebanon toward the northern Israeli town of Shlomi. In another incident, Israel protested the firing of a Katyusha rocket from the Gaza Strip to an area north of Ashkelon.