diff --git a/apps/ios/Shared/Model/SimpleXAPI.swift b/apps/ios/Shared/Model/SimpleXAPI.swift
index af5f3c3ee9..be2cde7cd6 100644
--- a/apps/ios/Shared/Model/SimpleXAPI.swift
+++ b/apps/ios/Shared/Model/SimpleXAPI.swift
@@ -2914,23 +2914,19 @@ func processReceivedMsg(_ res: ChatEvent) async {
             m.callInvitations[invitation.contact.id] = invitation
         }
         activateCall(invitation)
-    case let .callOffer(_, contact, callType, offer, sharedKey, _):
+    case let .callOffer(_, contact, callType, offer, sharedKey, askConfirmation):
         await withCall(contact) { call in
             await MainActor.run {
                 call.callState = .offerReceived
                 call.sharedKey = sharedKey
             }
-            let useRelay = UserDefaults.standard.bool(forKey: DEFAULT_WEBRTC_POLICY_RELAY)
-            let iceServers = getIceServers()
-            logger.debug(".callOffer useRelay \(useRelay)")
-            logger.debug(".callOffer iceServers \(String(describing: iceServers))")
-            await m.callCommand.processCommand(.offer(
-                offer: offer.rtcSession,
-                iceCandidates: offer.rtcIceCandidates,
-                media: callType.media, aesKey: sharedKey,
-                iceServers: iceServers,
-                relay: useRelay
-            ))
+            if askConfirmation {
+                showUnencryptedCallAlert(call) {
+                    Task { await processCallOffer(callType, offer, sharedKey) }
+                }
+            } else {
+                await processCallOffer(callType, offer, sharedKey)
+            }
         }
     case let .callAnswer(_, contact, answer):
         await withCall(contact) { call in
@@ -3067,6 +3063,43 @@ func processReceivedMsg(_ res: ChatEvent) async {
             logger.debug("processReceivedMsg: ignoring \(res.responseType), not in call with the contact \(contact.id)")
         }
     }
+
+    func processCallOffer(_ callType: CallType, _ offer: WebRTCSession, _ sharedKey: String?) async {
+        let useRelay = UserDefaults.standard.bool(forKey: DEFAULT_WEBRTC_POLICY_RELAY)
+        let iceServers = getIceServers()
+        logger.debug(".callOffer useRelay \(useRelay)")
+        logger.debug(".callOffer iceServers \(String(describing: iceServers))")
+        await m.callCommand.processCommand(.offer(
+            offer: offer.rtcSession,
+            iceCandidates: offer.rtcIceCandidates,
+            media: callType.media, aesKey: sharedKey,
+            iceServers: iceServers,
+            relay: useRelay
+        ))
+    }
+
+    func showUnencryptedCallAlert(_ call: Call, onContinue: @escaping () -> Void) {
+        DispatchQueue.main.async {
+            showAlert(
+                NSLocalizedString("Call is not encrypted", comment: "alert title"),
+                message: String.localizedStringWithFormat(NSLocalizedString("%@ accepted the call without end-to-end encryption.", comment: "alert message"), call.contact.displayName),
+                actions: {[
+                    UIAlertAction(title: NSLocalizedString("End call", comment: "alert action"), style: .destructive) { _ in
+                        // the call may have ended, or a new one started with the same contact, while the alert was shown
+                        guard m.activeCall === call else { return }
+                        if let uuid = call.callUUID {
+                            CallController.shared.endCall(callUUID: uuid)
+                        } else {
+                            CallController.shared.endCall(call: call) {}
+                        }
+                    },
+                    UIAlertAction(title: NSLocalizedString("Continue", comment: "alert action"), style: .default) { _ in
+                        if m.activeCall === call { onContinue() }
+                    }
+                ]}
+            )
+        }
+    }
 }
 
 func switchToLocalSession() {
diff --git a/apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/model/SimpleXAPI.kt b/apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/model/SimpleXAPI.kt
index 96515fbde2..e3bea95c03 100644
--- a/apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/model/SimpleXAPI.kt
+++ b/apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/model/SimpleXAPI.kt
@@ -3371,20 +3371,13 @@ object ChatController {
         chatModel.callManager.reportNewIncomingCall(r.callInvitation.copy(remoteHostId = rhId))
       }
       is CR.CallOffer -> {
-        // TODO askConfirmation?
-        // TODO check encryption is compatible
         withCall(r, r.contact) { call ->
           chatModel.activeCall.value = call.copy(callState = CallState.OfferReceived, hasSharedKey = r.sharedKey != null)
-          val useRelay = appPrefs.webrtcPolicyRelay.get()
-          val iceServers = getIceServers()
-          chatModel.callCommand.add(WCallCommand.Offer(
-            offer = r.offer.rtcSession,
-            iceCandidates = r.offer.rtcIceCandidates,
-            media = r.callType.media,
-            aesKey = r.sharedKey,
-            iceServers = iceServers,
-            relay = useRelay
-          ))
+          if (r.askConfirmation) {
+            showUnencryptedCallAlert(call) { processCallOffer(r) }
+          } else {
+            processCallOffer(r)
+          }
         }
       }
       is CR.CallAnswer -> {
@@ -3640,6 +3633,39 @@ object ChatController {
     }
   }
 
+  private fun processCallOffer(r: CR.CallOffer) {
+    val useRelay = appPrefs.webrtcPolicyRelay.get()
+    val iceServers = getIceServers()
+    chatModel.callCommand.add(WCallCommand.Offer(
+      offer = r.offer.rtcSession,
+      iceCandidates = r.offer.rtcIceCandidates,
+      media = r.callType.media,
+      aesKey = r.sharedKey,
+      iceServers = iceServers,
+      relay = useRelay
+    ))
+  }
+
+  private fun showUnencryptedCallAlert(call: Call, onContinue: () -> Unit) {
+    // the call may have ended, or a new one started with the same contact, while the alert was shown
+    fun offerPending(): Boolean {
+      val c = chatModel.activeCall.value
+      return c != null && c.remoteHostId == call.remoteHostId && c.contact.id == call.contact.id && c.callState == CallState.OfferReceived
+    }
+    val endCall = { if (offerPending()) withBGApi { chatModel.callManager.endCall(call) } }
+    AlertManager.shared.showAlertDialog(
+      title = generalGetString(MR.strings.call_not_encrypted_title),
+      text = generalGetString(MR.strings.call_not_encrypted_desc).format(call.contact.displayName),
+      confirmText = generalGetString(MR.strings.call_service_notification_end_call),
+      onConfirm = { endCall() },
+      dismissText = generalGetString(MR.strings.continue_to_next_step),
+      onDismiss = { if (offerPending()) onContinue() },
+      onDismissRequest = { endCall() },
+      destructive = true,
+      parseHtml = false
+    )
+  }
+
   suspend fun leaveGroup(rh: Long?, groupId: Long) {
     val groupInfo = apiLeaveGroup(rh, groupId)
     if (groupInfo != null) {
diff --git a/apps/multiplatform/common/src/commonMain/resources/MR/base/strings.xml b/apps/multiplatform/common/src/commonMain/resources/MR/base/strings.xml
index efe0423aff..8a8aad0cfa 100644
--- a/apps/multiplatform/common/src/commonMain/resources/MR/base/strings.xml
+++ b/apps/multiplatform/common/src/commonMain/resources/MR/base/strings.xml
@@ -1415,6 +1415,8 @@
   <string name="status_no_e2e_encryption">no e2e encryption</string>
   <string name="status_contact_has_e2e_encryption">contact has e2e encryption</string>
   <string name="status_contact_has_no_e2e_encryption">contact has no e2e encryption</string>
+  <string name="call_not_encrypted_title">Call is not encrypted</string>
+  <string name="call_not_encrypted_desc">%s accepted the call without end-to-end encryption.</string>
   <string name="call_connection_peer_to_peer">peer-to-peer</string>
   <string name="call_connection_via_relay">via relay</string>
   <string name="icon_descr_hang_up">Hang up</string>
diff --git a/src/Simplex/Chat/Library/Subscriber.hs b/src/Simplex/Chat/Library/Subscriber.hs
index 19b78dc2ae..71337a6b0e 100644
--- a/src/Simplex/Chat/Library/Subscriber.hs
+++ b/src/Simplex/Chat/Library/Subscriber.hs
@@ -3053,7 +3053,7 @@ processAgentMessageConn cxt user@User {userId} entity gks_ corrId agentConnId ag
             | callVersion `isCompatible` callVR -> do
                 let sharedKey = callMediaKey callVersion callId <$> callDhPubKey <*> localDhPrivKey
                     callState' = CallOfferReceived {localCallType, peerCallType = callType, peerCallSession = rtcSession, sharedKey}
-                    askConfirmation = encryptedCall localCallType && not (encryptedCall callType)
+                    askConfirmation = encryptedCall localCallType && isNothing sharedKey
                 toView CEvtCallOffer {user, contact = ct, callType, offer = rtcSession, sharedKey, askConfirmation}
                 pure (Just call {callState = callState'}, Just . ACIContent SMDSnd $ CISndCall CISCallAccepted 0)
             | otherwise -> do