Israel has set up an internal inquiry into its deadly raid last month on a convoy of Gaza-bound aid ships.
Israel earlier rejected a UN proposal for an international probe, but has now agreed to include two foreign observers in its own inquiry.
Nine Turkish activists were killed when Israeli commandos stormed the ships in international waters on 31 May.
Meanwhile, Middle East peace envoy Tony Blair says he hopes Israel will allow more humanitarian items into Gaza.
Washington welcomed the announcement of the inquiry, describing it as "an important step forward".
But Turkey's foreign minister said Ankara had "no trust at all" that Israel would conduct an impartial investigation.
Speaking to the BBC, Mr Blair said that Israeli Prime Minister Benjamin Netanyahu had agreed in principle to move from a list of items that are currently permitted into Gaza into a list of prohibited goods - and that was a "significant change".
Mr Blair added that the Israeli government would consider the plan in the coming days.
He was speaking before briefing European Union foreign ministers at talks on the Gaza blockade in Brussels.
The International Committee of the Red Cross (ICRC) has said Israel's blockade of Gaza is a clear violation of international humanitarian law.
In a statement, the ICRC described the situation in Gaza as dire, saying the only sustainable solution was a lifting of the blockade.
Last month's clashes came after six ships carrying campaigners and 10,000 tonnes of aid sailed from Cyprus in an attempt to break Israel's three-year blockade of the Hamas-run Gaza Strip.
Israel says its troops acted in self-defence when activists attacked commandos trying to board the main vessel in the flotilla. The campaigners say the soldiers opened fire without any provocation.
The proposal for an Israeli inquiry into the Gaza convoy raid was approved by the country's cabinet on Monday.
"The government decision will make it clear to the world that Israel is acting legally, responsibly, and with complete transparency," Mr Netanyahu told the cabinet, according to Haaretz newspaper.
The three-man panel will be led by former Israeli Supreme Court judge Yaakov Tirkel. The other members are Amos Horev, a retired major-general in the Israeli military and a former president of the Israel Institute of Technology, and Shabtai Rosen, a professor of international law.
But the premise of the inquiry was quickly criticised by Turkey.
"We have no trust at all that Israel, a country that has carried out such an attack on a civilian convoy in international waters, will conduct an impartial investigation," said Foreign Minister Ahmet Davutoglu.
"To have a defendant acting simultaneously as both prosecutor and judge is not compatible with any principle of law."
The AFP news agency also reported Palestinian Authority President Mahmoud Abbas as saying that the terms of the inquiry would not comply with demands made by the UN Security Council.
The two foreign experts - former Northern Ireland first minister and Nobel Peace Prize winner David Trimble and retired Canadian military prosecutor Ken Watkin - will take part in the hearings and subsequent discussions, but they will not vote on the conclusions of the inquiry.
Lord Trimble, the former Ulster Unionist leader, won the Nobel prize for his role in the 1998 Good Friday Agreement, which brought an end to the worst of the political violence in Northern Ireland. Since stepping aside from politics there, he has travelled to the Middle East to speak about conflict resolution.