Turkey's prime minister said Wednesday his country would never back down on demands for an apology from Israel over its 2010 commando raid on a Gaza-bound aid flotilla that killed nine Turkish activists.

"As long as Israel does not apologise, pay compensation and remove the embargo over Gaza, it is impossible to heal relations between Turkey and Israel," Prime Minister Recep Tayyip Erdogan told reporters in Istanbul.

"It is out of the question to step back from our determination on this issue," Erdogan said, as he left an emergency meeting of the Organisation of Islamic Cooperation on Somalia's drought.

Both Turkey and the families of victims would take new steps on the issue, Erdogan said. "A new process will start," he said, without elaborating.

According to Israeli media reports Wednesday, Israel has rejected a US request to apologise to Turkey over the raid on the Mavi Marmara, the flagship of a flotilla attempting to break Israel's naval embargo on the Gaza Strip.

The botched operation left nine Turkish nationals dead and sparked a diplomatic crisis with Ankara, which immediately recalled its ambassador.

A United Nations report into the flotilla affair, whose publication has been postponed at least twice this year to allow time for the two sides to reconcile their differences, is due to be released on August 20.