Turkish Prime Minister Recep Tayyip Erdogan has said his country will in future escort aid ships travelling to the Gaza Strip.
Speaking to Al Jazeera, Mr Erdogan also said Turkey had taken steps to prevent Israel unilaterally exploiting natural resources in the eastern Mediterranean.
He spoke amid a growing row over Israel's refusal to apologise for a deadly raid on an aid ship last year.
Turkey has already cut military ties and expelled Israel's ambassador.
It has also said it will challenge Israel's blockade of Gaza at the International Court of Justice (ICJ).
Relations between Turkey and Israel have worsened since Israeli forces boarded the Mavi Marmara aid ship in May last year as it was heading for Gaza. Nine Turkish activists were killed during the raid.
Israel has refused to apologise and said its troops acted in self-defence.
In his comments to Al-Jazeera, Mr Erdogan said Turkish warships were "authorised to protect our ships that carry humanitarian aid to Gaza".
"From now on, we will not let these ships to be attacked by Israel, as what happened with the Freedom Flotilla," he said, referring to the Mavi Marmara incident.
The BBC's Jonathan Head in Istanbul says Turkey's decision to increase its naval presence in the eastern Mediterranean - and not just to deter Israeli operations against Gaza activists - is a serious one.
Turkey is protesting against the exploration of gas reserves by the government of Cyprus, because it does not recognise the area as Cypriot territorial waters.
Israel has recognised them, and hopes to source future natural gas supplies there.
This could spark a conflict that mixes the current Turkish-Israeli friction with the 50-year-old dispute over Cyprus, our correspondent says.
"You know that Israel has begun to declare that it has the right to act in exclusive economic areas in the Mediterranean," said Mr Erdogan.
"You will see that it will not be the owner of this right, because Turkey, as a guarantor of the Turkish republic of north Cyprus, has taken steps in the area, and it will be decisive and holding fast to the right to monitor international waters in the east Mediterranean."
In response to Mr Erdogan's comments, Israeli Foreign Ministry spokesman Yigal Palmor was quoted by Reuters news agency as saying: "This is a statement well-worth not commenting on."