Turkish President Recep Tayyip Erdogan on Saturday called Western powers "the main culprit" behind the Israeli army's "massacre" of Palestinians in Gaza.
The Turkish leader has been a leading international supporter of Palestinian rights during his two-decade rule.
He took a more cautious line in the first days after Hamas militants staged a surprise attack on October 7 during which they seized more than 220 hostages and claimed more than 1,400 lives.
But he has become much more vocal as the reported death toll from Israel's military response has grown.
The Hamas-controlled health ministry in Gaza said Israeli strikes had killed 7,703 people -- mainly civilians -- with more than 3,500 of them children.
Erdogan's Islamic-rooted party staged a massive pro-Palestinian rally in Istanbul on Saturday that the Turkish leader said had drawn a crowd of 1.5 million.
He unleashed a scathing attack at Israel and its Western supporters after taking the stage with a microphone in his hand.
"The main culprit behind the massacre unfolding in Gaza is the West," Erdogan told the Turkish and Palestinian flag-waving crowd.
"If we leave aside some conscientious voices... the massacre in Gaza is entirely the work of the West."
Erdogan added that Israel was behaving like a "war criminal".
"Of course, every country has the right to defend itself. But where is the justice in this case?"
He accused Western powers of "shedding tears" over the death of civilians in Ukraine and turning a blind eye on the death of Palestinian civilians in Gaza.
"We are against all these double standards and all these hypocrisies," he said.
And he accused Israel's allies of creating a "crusade war atmosphere" pitting Christians against Muslims.
"Listen to our call for dialogue," Erdogan said. "No one loses from a just peace."