Turkish President Tayyip Erdogan on Friday said German Chancellor Angela Merkel's Christian Democrats were enemies of Turkey and called on Turks in Germany to vote against major parties in next month's elections, Reuters reports.

"I am calling on all my countrymen in Germany: the Christian Democrats, SDP, the Green Party are all enemies of Turkey. Support those political parties who are not enemies of Turkey," he said in comments after Friday prayers in Istanbul.

"I call on them not to vote for those parties who have been engaged in such aggressive, disrespectful attitudes against Turkey, and I invite them to teach a lesson to those political parties at the ballot box," he said.

The comments are some of Erdogan's harshest yet against Merkel and her Christian Democrats, illustrating the widening divide between the NATO allies and major trade partners.

Ties between Ankara and Berlin have been strained in the aftermath of last year's failed coup as Turkish authorities have sacked or suspended 150,000 people and detained more than 50,000 people, including German nationals.

Germany has voiced concern that Erdogan is using the coup as a pretext to quash dissent. Erdogan, an authoritarian leader whose roots are in political Islam, has accused Germany of anti-Turkish and anti-Muslim sentiment.