Turkey is to challenge Israel's blockade on Gaza at the International Court of Justice, amid a worsening diplomatic crisis between the once close allies.
The announcement by Turkish foreign minister Ahmet Davutoglu appears to rebuff UN secretary general Ban Ki-moon's attempt to defuse the row over Israel's armed assault on a Gaza-bound aid flotilla in which nine people were killed.
Turkey dramatically downgraded its relations with Israel, cutting military ties with its former ally and expelling the country's ambassador over his government's refusal to apologise for the killings of eight Turkish citizens and a Turkish American last May.
Ban said today that the two countries should accept the recommendations of a UN report that examined the incident. The report found Israel had used "excessive and unreasonable" force to stop the flotilla approaching Gaza, but that it was justified in maintaining a naval blockade on the Palestinian enclave.
But Davutoglu later dismissed the report, stating it had not been endorsed by the UN and was therefore not binding.
"What is binding is the International Court of Justice," he told Turkey's state-run TRT television. "This is what we are saying: let the International Court of Justice decide.
"We are starting the necessary legal procedures this coming week."
Israeli deputy foreign minister Danny Ayalon said his country had nothing to apologise for and accused Ankara of raising tensions for its own reasons.
"The problem here is on the Turkish side …. They were not ready for a compromise and kept raising the threshold," Ayalon said on Israeli TV. "I think we need to say to the Turks: as far as we are concerned, this saga is behind us. Now we need to cooperate. Lack of cooperation harms not only us, but Turkey as well."
The UN investigation, chaired by Geoffrey Palmer, a former New Zealand prime minister, focused on the events on the Mavi Marmara, a Turkish-flagged vessel which was the largest ship in a flotilla aimed at breaking the Gaza blockade, on 31 May last year. It was boarded by Israeli commandos who were met with resistance by spro-Palestinian activists on board, nine of whom died.
Davutoglu said the investigation contradicted an earlier report by the UN Human Rights Council in September, which found Israeli forces violated international law, "including international humanitarian and human rights law".
He warned Israel that it risks alienation among Arab nations by resisting an apology.
"If Israel persists with its current position, the Arab spring will give rise to a strong Israel opposition, as well as the debate on the authoritarian regimes," Davutoglu said.
The UN secretary general said earlier that strong ties between Turkey and Israel, which both share a border with Syria, were important for peace and stability in the Middle East. "I sincerely hope that Israel and Turkey will improve their relationship," he added.
"Both countries are very important countries in the region, and their improved relationship will be very important in addressing all the situations in the Middle East, including the Middle East peace process."
But Ban, speaking in Canberra on Saturday after talks with the Australian prime minister, Julia Gillard, would not be drawn on findings of the UN report on the flotilla incident last summer.
"I'm not in a position to say any specific comments on the substance of the findings and recommendations of the panel's report," he said.
"My only wish is that they should try to improve their relationship and do what they can to implement the recommendations and findings."
Turkey said on Friday that the Israeli ambassador, Gabby Levy, and other senior Israeli diplomats would have to leave their posts by Wednesday and that Turkey's representation in Israel would be downgraded to the junior level of second secretary.