The Turkish president has also said Europe is regressing to the pre-World War II era. German Chancellor Angel Merkel called for an end to the exchange of “insults.”

In a speech given to supporters in the western Turkish city of Sakarya, President Recep Tayyip Erdogan invoked the medieval religious wars between Christian Europe and the Islamic Middle East in the context of present-day escalating tensions between the European Union and Turkey.

“My dear brothers, a battle has started between the cross and the half moon. There can be no other explanation,” Erdogan said on Thursday.

The Turkish president also stated the European Court of Justice’s (ECJ) Tuesday ruling, which permits companies to ban the Islamic headscarf as part of policies barring religious symbols in the workplace, was the start of a “crusade” by Europe.

Erdogan has recently upped his antagonistic rhetoric towards Europe after Germany and the Netherlands both canceled campaign appearances by Turkish politicians. The events were intended to drum up support for an April 16 referendum that, if approved, would vastly expand Erdogan’s presidential powers.

Erdogan has repeatedly compared the behavior of German and Dutch politicians to that of “Nazis” and accused Europe of hosting the “spirit of fascism.”

“Europe is swiftly rolling back to the days before World War II,” he said in his speech in Sakarya.

Post-election attacks on the Netherlands

Erdogan and Turkish Foreign Minister Mevlut Cavusoglu also took aim at the Netherlands on Thursday despite the previous day’s election result, in which Dutch voters rejected right-wing populist Geert Wilders and his Islamophobic and anti-immigration platform.

“Hey Rutte! You may have emerged as the number one party in the election but you must know that you have lost Turkey as your friend,” Erdogan said in his televised speech.

Many analysts believe Rutte’s hardline approach to prohibiting Turkish politicians from campaigning in the Netherlands helped him gain the support of undecided voters who buoyed him to victory over Wilders.

Despite Turkey’s previous criticism of the virulently anti-Islam Wilders, Cavusoglu told a Turkish broadcaster on Thursday that there was “no difference” between the liberal Rutte and “fascist” Wilders.

The antagonistic rhetoric and authoritarian power expansions, as well as Ankara’s threats to suspend the 2016 migration agreement with the EU, has thrown the EU neighbor’s long-standing bid for entry into the bloc into question.

Merkel: ‘The insults need to stop’

For her part, German Chancellor Angela Merkel denounced Erdogan’s latest round of accusations. The Turkish president accused Merkel this week of supporting terrorists in the anti-Erdogan Kurdistan Workers’ Party (PKK).

“I don’t intend to participate in this race to trade provocations,” she told the German regional newspaper “Saarbrücker  Zeitung.”

“The insults need to stop,” she added in comments printed in the paper’s Friday edition, referencing Turkey’s Nazi comparisons aimed at the Netherlands.

Merkel stated that Turkish political leaders are permitted to appear in the country under certain conditions: they must disclose who will appear and for what goal, and the foreign politicians must abide by Germany’s laws and constitutional principles.

“We do not give anyone a carte blanche for the future,” she added.

The chancellor’s comments came the same day the city of Hannover scrapped a Friday rally organized by the Union of European Turkish Democrats (UETD) at which a senior Erdogan government official was set to appear.

The last-minute cancellation indicates tempers could get hotter and the Turkish-German relationship perhaps even cooler.