Microsoft is now working on a new feature for Microsoft Teams, that will support an option to use end-to-end encryption (E2EE) for ad hoc 1:1 Teams VoIP calls. If you are using Teams voice call, this feature will add additional security for conducting sensitive online conversations.
Microsoft confirmed this feature in the Microsoft 365 Roadmap, and the company is planning to release this feature next month with the July 2021 update.