German officials have rejected a request by Turkish President Recep Tayyip Erdogan to address ethnic Turks in Germany, citing security concerns and strained relations between the two countries.

German Foreign Minister Sigmar Gabriel said Thursday that Berlin had received a request from Turkey if there would be a possibility for Erdogan to speak to members of the Turkish diaspora in Germany next week when he travels to the EU country to attend a G20 summit.

“I explained weeks ago to my Turkish colleagues that we don't think that would be a good idea,” Gabriel said, adding, “I also said quite frankly that such an appearance would not be appropriate given the current adversarial situation with Turkey.”

The top German diplomat, who was on a trip to Russia, said stretched police resources would be needed around the G20 summit in Hamburg on July 7-8, effectively making it difficult for German authorities to ensure security of an Erdogan speech. He stressed that Erdogan would, however, be "received with honors" at the summit.

Tensions have soured between Berlin and Ankara since a failed coup in Turkey in July last year. Germany has repeatedly criticized Turkey for a massive crackdown that was launched right after the coup, saying the action has been carried out beyond the rule of law.

The two countries have also clashed on several other issues, including Germany’s alleged support for Kurdish opponents and a referendum in Turkey last April, which gave Erdogan sweeping new powers.

Justifying Germany’s refusal to grant Erdogan a speech, Gabriel, from Germany’s Social Democratic Party, also pointed to comments by his party chief and chancellor candidate Martin Schulz, who had earlier called on the government to bloc politicians like Erdogan from holding mass events in Germany.

"I don't want Mr. Erdogan, who is jailing members of the opposition and journalists in Turkey, to hold large-scale events in Germany," Schulz told Bild newspaper, adding, “Foreign politicians who abuse our values must not be allowed to give inflammatory speeches in Germany.”

Germany is home to some three million ethnic Turks. The country allowed in the Turks in the 1960s and 1970s as part of its massive post-war "guest worker" program. Erdogan held his last speech to members of the community in May 2015 in the city of Karlsruhe.