Some of Germany’s allies are urging Berlin to tighten security around classified information after Russia revealed sensitive discussions about aid for Ukraine, people familiar with the discussions have said.

Officials from NATO countries expressed concern about seemingly careless operational security that resulted in the leak of a conversation between German military officers, including the use of commercial, nonencrypted platform WebEx for the meeting.

One called the lackadaisical measures unprofessional, and said that such behavior would be expected from people who have never had security briefings but not from military officials. Another said they were not surprised by the lapse from Germany, while a third said the leak would likely result in tighter measures across the board, but particularly in Germany. All asked not to be named due to the sensitivity of the matter.