Turkish Prime Minister Ahmet Davutoglu accused his Israeli counterpart Benjamin Netanyahu on Friday of terrorism and said Israeli "provocations" such as the bombardment of Gaza were contributing to radicalisation in the Muslim world.
In a Reuters interview, Davutoglu said peace in the Middle East and the eradication of extremist groups would be virtually impossible without the establishment of a Palestinian state.
He also warned the international community against focusing solely on fighting Islamic State militants in its efforts to end the conflict in Syria, saying the "brutality" of President Bashar al-Assad was the root cause of the problem.
Turkey, an EU candidate nation and member of the NATO military alliance, is a key Western ally in the fight against Islamic jihadists. But its leaders have become increasingly concerned about what they see as rising Islamophobia in Europe and increasingly outspoken in their criticism of Israel.
"(Netanyahu) himself killed, his army killed children in the playground. They killed our citizens and an American citizen in international waters. This is terrorism," Davutoglu said, referring to a 2010 Israeli assault on a Turkish boat attempting to break Israel's blockade of the Palestinian Gaza Strip.
"Nobody can argue about Israeli aggression in Jerusalem in the al-Aqsa mosque," he added. "These provocations create frustration in the Muslim world and are becoming one of the reasons why these radical trends are emerging," he said.
"If we want to establish peace and order in the Middle East, eliminating all the extremist forces, we have to solve the Palestinian question."
Davutoglu on Thursday compared Netanyahu to the Islamist militants who killed 17 people in Paris last week, saying both had committed crimes against humanity.
Netanyahu has called for an international condemnation of Davutoglu's remarks and those of President Tayyip Erdogan, after he criticised the Israeli prime minister's attendance with other world leaders at a solidarity march in Paris.
Once-good relations between Israel and Turkey have declined markedly over the past five years, with US-efforts to revive the soured ties failing to make headway. There was no immediate reaction in Israel to Davutoglu's latest comments.
Davutoglu said Turkey, which has faced criticism for failing to stop thousands of foreign fighters crossing into Syria, would do everything it could to stem the flow, describing the conflict in its southern neighbor as a major national security threat.
But he said a coherent strategy was needed for Syria before Turkey would consider a greater front-line role in the US-led coalition against Islamic State, including an internationally policed no-fly zone to protect the northern city of Aleppo from Assad's forces.
"The source of the problem is the Assad regime's brutality. Without solving that source, that reason, dealing only with (Islamic State) or other bi-products of this crisis will not be solving the problem altogether," Davutoglu said.
"(We want a) no-fly zone ... so that Aleppo will be protected at least against the air bombardment and there will be no new refugees coming to Turkey," he said, warning of a potential new influx of millions if the city was not defended.
He said Turkey may extend a series of existing militarized zones along its border with Syria to try to stop the passage of foreign fighters without closing the frontier to refugees.
"On the border, up to now, there are refugee camps, there are certain places where there is much more strict control ... These military zones might be enlarged," he said, adding Turkeyhad so far been reluctant to do so, so as not to deter refugees.
The Turkish authorities had banned some 8,000 foreigners from entering the country over the past year alone because of security concerns and had further improved coordination with European intelligence agencies, Davutoglu said.
On the domestic political front, Davutoglu said he expected a request to be made to the US authorities for the extradition of Muslim cleric Fethullah Gulen, accused by Erdogan and the government of leading a plot to seize power.
A Turkish court issued an arrest warrant in December for Gulen, who has lived in self-imposed exile in Pennsylvania since 1999. Asked if an extradition request would now follow, Davutoglu said:
"Yes, of course, if needed yes. It is not our choice, it is the decision of the court, not the decision of the government. The government will do whatever is needed," he said.
Such a move would take Erdogan's campaign to root out Gulen supporters, including purges of the judiciary and police, to the international arena and potentially test strained relations with Washington.
Turkey and the United States have a treaty that allows extraditions in certain instances, and requires that there is enough evidence to charge the same defendant with a crime under both Turkish and US law. The treaty also allows the United States to refuse an extradition request if it deems it political in nature. A spokesman for the US Justice Department, which would handle the request, declined comment.
Alp Aslandogan, a Turkish-American academic close to Gulen, said Davutoglu's comments were "another politically motivated attempt to persecute law-abiding citizens for engaging in democratic dissent and carry no credibility". He said he had not been informed of formal charges against Gulen.
Gulen was a close ally of Erdogan in the early years after his ruling AK Party took power in 2002 but has been in open conflict with him since a graft investigation emerged just over a year ago targeting the then-prime minister's inner circle.
Erdogan and Davutoglu portray the investigation as part of a coup attempt and have described Gulen's followers as traitors — charges that Gulen, who runs a vast network of schools and business enterprises in Turkey and abroad, denies.