President Tayyip Erdogan addressed hundreds of thousands of supporters at one of the largest pro-Palestinian rallies since the Israel-Hamas war began, courting his Islamist political base a day ahead of the centenary of Turkey's secular republic.
"Israel has been openly committing war crimes for 22 days, but the Western leaders cannot even call on Israel for a ceasefire, let alone react to it," Erdogan told the crowd in Istanbul, who waved Palestinian flags.
"We will tell the whole world that Israel is a war criminal. We are making preparations for this. We will declare Israel a war criminal," he said.
In an hour-long speech, Erdogan also repeated his assertion that Hamas was not a terrorist organisation, describing Israel as an occupier.
Erdogan calls Hamas 'freedom fighters', angering Israel
Turkey to mark anniversary of secular republic's founding
Mass rally could overshadow centenary celebrations
Turkey has condemned Israeli civilian deaths caused by Hamas's Oct 7 rampage through southern Israel, which killed 1,400, but Erdogan this week called the militant group Palestinian "freedom fighters".
He also criticised some Western nations' unconditional support for Israel, drawing sharp rebukes from Italy and Israel.
Unlike many NATO allies, the European Union and some Gulf states, Turkey does not consider Hamas a terrorist organisation. It has long hosted its members, supports a two-state solution and has offered to play a role in negotiating the release of hostages abducted by Hamas during the Oct. 7 assault.
Political analysts said Erdogan was keen to reinforce his criticism of Israel's bombardment of the Gaza Strip and to overshadow Sunday's celebrations marking Turkey's secular roots.
Sinan Ulgen, a former Turkish diplomat and director of the Centre for Economic and Foreign Policy Studies, an Istanbul-based think-tank, said Gaza's worsening humanitarian crisis and pressure from political allies had prompted Erdogan to sharpen his rhetoric.
Turkey "will protect its principles and share these with the international community, but it needs to do this with a more delicate diplomacy if it expects to play such a diplomatic role," Ulgen said.
The heads of allied nationalist and Islamist parties - which helped Erdogan secure victory in tight May elections - attended the rally at Istanbul's old airport. Erdogan criticised opposition parties for not calling Netanyahu a "terrorist" and for using the same term with reference to Hamas.
Erdogan had invited all Turks to attend the rally where he said "only our flag and the Palestine flag will wave". His Islamist-rooted AK Party had predicted more than a million people would come.
Modern Turkey's 100th anniversary comes on Sunday, when newspaper headlines could be dominated by news of the Saturday rally rather than celebrations of the republic's founder, Mustafa Kemal Ataturk, analysts say.
Erdogan, Turkey's longest-serving leader, and his AK Party have eroded support for the Western-facing ideals of Ataturk, who is revered by most Turks. In recent years, Erdogan's portraits have appeared alongside those of Ataturk on government buildings and schools.
"The symbolism is clear and no one in Turkey is unaware of it - that the pro-Palestinian rally is likely to overshadow celebrations for the centennial of the secular republic," said Asli Aydintasbas, visiting fellow at the Washington-based Brookings Institution.
She said that while Erdogan's comments about Hamas reflected Ankara's long-held position, he aimed to benefit from anti-Israel sentiment domestically and "consolidate Turkey's Sunni conservatives".
The government has said the Israel-Hamas conflict will not restrict celebrations of the 100th anniversary, for which it has organised events across the country.