As France mourns the lives lost in a knife attack at a church in Nice, German President Frank-Walter Steinmeier condemned the violence in an exclusive interview with DW on Friday.

He said his thoughts "are above all with the relatives" of the three victims who were killed. At the same time, he called for a response that is not dictated by "hate."

"I believe what we in Europe, and not just in France, must do now is to stand up to this act of brutality and the Islamist motives behind it. In our democratic societies, above all, we should not base the response of the state on a course determined by hate and xenophobia," Steinmeier said.

Trying to strike a balance between standing up to the violence while defending open societies and tolerance presents a unique challenge, he noted.

"Acceptance and mutual respect are a part of our society. Standing up to such acts of brutal violence, and Islamist motives is one thing, the other is to try and maintain the openness of our society — that's the other challenge," the German president said.

The main suspect in the attack in Nice has been identified as a 21-year-old Tunisian man who was shot by police and hospitalized in life-threatening condition. The suspect recently arrived in France and was not known as a suspected militant before he left Tunisia.

Erdogan's rhetoric 'not helpful'

Tensions have been rising between France and several Muslim-majority countries after French President Emmanuel Macron defended controversial cartoons of the Prophet Muhammad and decried Islamic "separatism." His remarks came after a teacher was beheaded this month for showing the caricatures in a civics lesson on freedom of speech. 

Turkey, in particular, has led the charge, with President Recep Tayyip Erdogan accusing Macron of having an anti-Muslim agenda and calling for a boycott of French products.

Steinmeier told DW there was "no question" that Erdogan's rhetoric "is not helpful at all."

Steinmeier added that he hopes that the "noticeably escalating rhetoric" in the dispute "does not encourage some possible perpetrators."

He emphasized that in the aftermath of the killings in Nice, several leaders of Muslim-majority countries condemned the attack.

"This is important and also a signal of what is understood within the Muslim communities in France."

The attack on Thursday is the third deadly attack to hit France in three months that authorities have attributed to terrorism.