Messaging encryption, widely used by Islamist extremists to plan attacks, needs to be fought at international level, French Interior Minister Bernard Cazeneuve said on Thursday, and he wants Germany to help him promote a global initiative.

He meets his German counterpart, Thomas de Maiziere, on Aug. 23 in Paris and they will discuss a European initiative with a view to launching an international action plan, Cazeneuve said.

French intelligence services are struggling to intercept messages from Islamist extremists who increasingly switch from mainstream social media to encrypted messaging services, with Islamic State being a big user of such apps, including Telegram.

“Many messages relating to the execution of terror attacks are sent using encryption; it is a central issue in the fight against terrorism,” Cazeneuve told reporters after a government meeting on security.

“France will make proposals. I have sent a number of them to my Germany colleague,” he said.

Cazeneuve declined to say whether France would request decryption techniques from service operators.

The man who slit the throat of an elderly French priest in the name of Islamic State last month frequently communicated with scores of followers on Telegram, which is widely used in the Middle East, Central and Southeast Asia, and Latin America.

Telegram promotes itself as ultra-secure because all data is encrypted from start to finish, known in the industry as end-to-end encryption. A number of other services, including Facebook’s WhatsApp (FB), say they have similar capabilities.

Germany’s de Maiziere said on Thursday that Germany lay in the “crosshairs of terrorism” and laid out plans for the military to train more closely with police authorities to prepare for potential large-scale militant attacks.