Paris: Israel must make amends to be forgiven for a commando assault on a Gaza-bound aid flotilla, Turkish President Abdullah Gul was reported as saying by the French daily Le Monde.
Israel must be made to apologise for the attack and pay compensation, and if Israel made no move to heal the rift, then Turkey may decide to break diplomatic relations, Gul said.
In an interview published on Friday, Gul was quoted as saying the Israeli attack at the end of May, which killed nine activists, was a "crime" which might have been carried out by the likes of Al Qaida rather than a sovereign state. "It seems impossible to me to forgive or forget, unless there are some initiatives which could change the situation," Gul said.
Asked what these might be, he said: "Firstly, to ask pardon and to establish some sort of compensation".
Gul said he wanted to see an independent inquiry into the botched raid and a discussion on lifting Israel's blockade of Gaza.
Asked if Turkey might break relations with Israel if they did nothing, Gul said: "Anything is possible."
Israeli soldiers shot and killed the nine Turkish nationals on May 31 after boarding a boat laden with humanitarian aid that was planning to breach the blockaded Gaza Strip.
Israel said its soldiers acted in self-defence after being attacked with knives and clubs.
Once a close ally of Israel, Turkey recalled its ambassador following the incident and cancelled joint military exercises.
It also said trade and defence deals worth billions of dollars would be reduced to a minimum.
Separately, Philip Alston, the UN special rapporteur on extra-judicial executions, said any inquiry set up by Israel to investigate the Gaza flotilla incident "must be given a genuine capacity to find the facts" or it would not be credible.
To comply with international standards such an inquiry would have to be independent of the government, he said.
It would need to have full legal authority to obtain direct access to all relevant evidence, including the military personnel involved, he said.
Israel has fended off a UN demand for an international investigation into the raid.
It has instead accepted a US proposal for an Israeli inquiry with the participation of outside observers.