diff --git a/src/core/CMakeLists.txt b/src/core/CMakeLists.txt
index 43a534b0a..fb697fa72 100644
--- a/src/core/CMakeLists.txt
+++ b/src/core/CMakeLists.txt
@@ -315,6 +315,7 @@ set(RADIO_COMMON_SOURCES
     radio/radio_callbacks.cpp
     radio/radio_platform.cpp
     thread/link_quality.cpp
+    utils/otns.cpp
     utils/parse_cmdline.cpp
     utils/power_calibration.cpp
 )
diff --git a/src/core/instance/instance.cpp b/src/core/instance/instance.cpp
index a61e25e86..ff6939a37 100644
--- a/src/core/instance/instance.cpp
+++ b/src/core/instance/instance.cpp
@@ -84,6 +84,9 @@ Instance::Instance(void)
 #if OPENTHREAD_CONFIG_UPTIME_ENABLE
     , mUptime(*this)
 #endif
+#if OPENTHREAD_CONFIG_OTNS_ENABLE
+    , mOtns(*this)
+#endif
 #if OPENTHREAD_MTD || OPENTHREAD_FTD
     , mNotifier(*this)
     , mTimeTicker(*this)
@@ -259,9 +262,6 @@ Instance::Instance(void)
 #if OPENTHREAD_CONFIG_ANNOUNCE_SENDER_ENABLE
     , mAnnounceSender(*this)
 #endif
-#if OPENTHREAD_CONFIG_OTNS_ENABLE
-    , mOtns(*this)
-#endif
 #if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
     , mRoutingManager(*this)
 #if OPENTHREAD_CONFIG_BORDER_ROUTING_TRACK_PEER_BR_INFO_ENABLE
diff --git a/src/core/instance/instance.hpp b/src/core/instance/instance.hpp
index 08f001a69..eede9f422 100644
--- a/src/core/instance/instance.hpp
+++ b/src/core/instance/instance.hpp
@@ -471,6 +471,10 @@ private:
     Uptime mUptime;
 #endif
 
+#if OPENTHREAD_CONFIG_OTNS_ENABLE
+    Utils::Otns mOtns;
+#endif
+
 #if OPENTHREAD_MTD || OPENTHREAD_FTD
     // Notifier, TimeTicker, Settings, and MessagePool are initialized
     // before other member variables since other classes/objects from
@@ -699,10 +703,6 @@ private:
     AnnounceSender mAnnounceSender;
 #endif
 
-#if OPENTHREAD_CONFIG_OTNS_ENABLE
-    Utils::Otns mOtns;
-#endif
-
 #if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
     BorderRouter::RoutingManager mRoutingManager;
 #if OPENTHREAD_CONFIG_BORDER_ROUTING_TRACK_PEER_BR_INFO_ENABLE
@@ -758,6 +758,10 @@ template <> inline Radio::Statistics &Instance::Get(void) { return mRadio.mStati
 template <> inline Uptime &Instance::Get(void) { return mUptime; }
 #endif
 
+#if OPENTHREAD_CONFIG_OTNS_ENABLE
+template <> inline Utils::Otns &Instance::Get(void) { return mOtns; }
+#endif
+
 #if OPENTHREAD_MTD || OPENTHREAD_FTD
 template <> inline Notifier &Instance::Get(void) { return mNotifier; }
 
@@ -1078,10 +1082,6 @@ template <> inline LinkMetrics::Subject &Instance::Get(void) { return mSubject;
 
 #endif // (OPENTHREAD_CONFIG_THREAD_VERSION >= OT_THREAD_VERSION_1_2)
 
-#if OPENTHREAD_CONFIG_OTNS_ENABLE
-template <> inline Utils::Otns &Instance::Get(void) { return mOtns; }
-#endif
-
 #if OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE
 template <> inline BorderRouter::RoutingManager &Instance::Get(void) { return mRoutingManager; }
 template <> inline BorderRouter::InfraIf        &Instance::Get(void) { return mRoutingManager.mInfraIf; }
diff --git a/src/core/radio/radio.cpp b/src/core/radio/radio.cpp
index f3f980e0f..05ed0c1dd 100644
--- a/src/core/radio/radio.cpp
+++ b/src/core/radio/radio.cpp
@@ -88,7 +88,7 @@ void Radio::SetExtendedAddress(const Mac::ExtAddress &aExtAddress)
     address.Set(aExtAddress.m8, Mac::ExtAddress::kReverseByteOrder);
     otPlatRadioSetExtendedAddress(GetInstancePtr(), &address);
 
-#if (OPENTHREAD_MTD || OPENTHREAD_FTD) && OPENTHREAD_CONFIG_OTNS_ENABLE
+#if OPENTHREAD_CONFIG_OTNS_ENABLE
     Get<Utils::Otns>().EmitExtendedAddress(address);
 #endif
 }
@@ -97,7 +97,7 @@ void Radio::SetShortAddress(Mac::ShortAddress aShortAddress)
 {
     otPlatRadioSetShortAddress(GetInstancePtr(), aShortAddress);
 
-#if (OPENTHREAD_MTD || OPENTHREAD_FTD) && OPENTHREAD_CONFIG_OTNS_ENABLE
+#if OPENTHREAD_CONFIG_OTNS_ENABLE
     Get<Utils::Otns>().EmitShortAddress(aShortAddress);
 #endif
 }
@@ -120,7 +120,7 @@ Error Radio::ClearSrcMatchExtEntry(const Mac::ExtAddress &aExtAddress)
 
 Error Radio::Transmit(Mac::TxFrame &aFrame)
 {
-#if (OPENTHREAD_MTD || OPENTHREAD_FTD) && OPENTHREAD_CONFIG_OTNS_ENABLE
+#if OPENTHREAD_CONFIG_OTNS_ENABLE
     Get<Utils::Otns>().EmitTransmit(aFrame);
 #endif
 
diff --git a/src/core/utils/otns.cpp b/src/core/utils/otns.cpp
index f9f0fe766..3d5559f37 100644
--- a/src/core/utils/otns.cpp
+++ b/src/core/utils/otns.cpp
@@ -33,7 +33,7 @@
 
 #include "otns.hpp"
 
-#if (OPENTHREAD_MTD || OPENTHREAD_FTD) && OPENTHREAD_CONFIG_OTNS_ENABLE
+#if OPENTHREAD_CONFIG_OTNS_ENABLE
 
 #include "instance/instance.hpp"
 
@@ -52,6 +52,42 @@ void Otns::EmitExtendedAddress(const Mac::ExtAddress &aExtAddress) const
     EmitStatus("extaddr=%s", revExtAddress.ToString().AsCString());
 }
 
+void Otns::EmitStatus(const char *aFmt, ...) const
+{
+    StatusString string;
+    va_list      args;
+
+    va_start(args, aFmt);
+    string.AppendVarArgs(aFmt, args);
+    va_end(args);
+
+    EmitStatus(string);
+}
+
+void Otns::EmitStatus(const StatusString &aString) const { otPlatOtnsStatus(aString.AsCString()); }
+
+void Otns::EmitTransmit(const Mac::TxFrame &aFrame) const
+{
+    StatusString string;
+    Mac::Address dst;
+
+    IgnoreError(aFrame.GetDstAddr(dst));
+
+    string.Append("transmit=%d,%04x,%d", aFrame.GetChannel(), aFrame.GetFrameControlField(), aFrame.GetSequence());
+
+    if (dst.IsShort())
+    {
+        string.Append(",%04x", dst.GetShort());
+    }
+    else if (dst.IsExtended())
+    {
+        string.Append(",%s", dst.ToString().AsCString());
+    }
+
+    EmitStatus(string);
+}
+
+#if OPENTHREAD_MTD || OPENTHREAD_FTD
 void Otns::EmitPingRequest(const Ip6::Address &aPeerAddress,
                            uint16_t            aPingLength,
                            uint32_t            aTimestamp,
@@ -70,20 +106,6 @@ void Otns::EmitPingReply(const Ip6::Address &aPeerAddress,
                aHopLimit);
 }
 
-void Otns::EmitStatus(const char *aFmt, ...) const
-{
-    StatusString string;
-    va_list      args;
-
-    va_start(args, aFmt);
-    string.AppendVarArgs(aFmt, args);
-    va_end(args);
-
-    EmitStatus(string);
-}
-
-void Otns::EmitStatus(const StatusString &aString) const { otPlatOtnsStatus(aString.AsCString()); }
-
 void Otns::HandleNotifierEvents(Events aEvents) const
 {
     if (aEvents.Contains(kEventThreadRoleChanged))
@@ -133,27 +155,6 @@ exit:
     return;
 }
 
-void Otns::EmitTransmit(const Mac::TxFrame &aFrame) const
-{
-    StatusString string;
-    Mac::Address dst;
-
-    IgnoreError(aFrame.GetDstAddr(dst));
-
-    string.Append("transmit=%d,%04x,%d", aFrame.GetChannel(), aFrame.GetFrameControlField(), aFrame.GetSequence());
-
-    if (dst.IsShort())
-    {
-        string.Append(",%04x", dst.GetShort());
-    }
-    else if (dst.IsExtended())
-    {
-        string.Append(",%s", dst.ToString().AsCString());
-    }
-
-    EmitStatus(string);
-}
-
 void Otns::EmitDeviceMode(Mle::DeviceMode aMode) const
 {
     StatusString string;
@@ -217,8 +218,9 @@ void Otns::EmitCoapStatus(const char             *aAction,
 exit:
     LogWarnOnError(error, "EmitCoapStatus");
 }
+#endif // OPENTHREAD_MTD || OPENTHREAD_FTD
 
 } // namespace Utils
 } // namespace ot
 
-#endif // (OPENTHREAD_MTD || OPENTHREAD_FTD) && OPENTHREAD_CONFIG_OTNS_ENABLE
+#endif // OPENTHREAD_CONFIG_OTNS_ENABLE
diff --git a/src/core/utils/otns.hpp b/src/core/utils/otns.hpp
index ddf854e4e..ca8625386 100644
--- a/src/core/utils/otns.hpp
+++ b/src/core/utils/otns.hpp
@@ -36,22 +36,24 @@
 
 #include "openthread-core-config.h"
 
-#if (OPENTHREAD_MTD || OPENTHREAD_FTD) && OPENTHREAD_CONFIG_OTNS_ENABLE
+#if OPENTHREAD_CONFIG_OTNS_ENABLE
 
 #include <openthread/thread.h>
 #include <openthread/thread_ftd.h>
 #include <openthread/platform/otns.h>
-
-#include "coap/coap_message.hpp"
 #include "common/locator.hpp"
 #include "common/non_copyable.hpp"
-#include "common/notifier.hpp"
 #include "common/string.hpp"
 #include "mac/mac_frame.hpp"
 #include "mac/mac_types.hpp"
+
+#if OPENTHREAD_MTD || OPENTHREAD_FTD
+#include "coap/coap_message.hpp"
+#include "common/notifier.hpp"
 #include "net/ip6_address.hpp"
 #include "thread/neighbor.hpp"
 #include "thread/neighbor_table.hpp"
+#endif
 
 namespace ot {
 namespace Utils {
@@ -61,7 +63,9 @@ namespace Utils {
  */
 class Otns : public InstanceLocator, private NonCopyable
 {
+#if OPENTHREAD_MTD || OPENTHREAD_FTD
     friend class ot::Notifier;
+#endif
 
 public:
     /**
@@ -88,6 +92,14 @@ public:
      */
     void EmitExtendedAddress(const Mac::ExtAddress &aExtAddress) const;
 
+    /**
+     * Emits a transmit event to OTNS.
+     *
+     * @param[in]  aFrame  The frame of the transmission.
+     */
+    void EmitTransmit(const Mac::TxFrame &aFrame) const;
+
+#if OPENTHREAD_MTD || OPENTHREAD_FTD
     /**
      * Emits ping request information to OTNS when sending.
      *
@@ -122,13 +134,6 @@ public:
      */
     void EmitNeighborChange(NeighborTable::Event aEvent, const Neighbor &aNeighbor) const;
 
-    /**
-     * Emits a transmit event to OTNS.
-     *
-     * @param[in]  aFrame  The frame of the transmission.
-     */
-    void EmitTransmit(const Mac::TxFrame &aFrame) const;
-
     /**
      * Emits the device mode to OTNS.
      *
@@ -159,8 +164,9 @@ public:
      * @param[in] aMessage      The received COAP message.
      * @param[in] aMessageInfo  The message info.
      */
-    void EmitCoapReceive(const Coap::Message &aMessage, const Ip6::MessageInfo &aMessageInfo) const;
 
+    void EmitCoapReceive(const Coap::Message &aMessage, const Ip6::MessageInfo &aMessageInfo) const;
+#endif // OPENTHREAD_MTD || OPENTHREAD_FTD
 private:
     static constexpr uint16_t kStatusStringLength = 128;
 
@@ -168,17 +174,19 @@ private:
 
     void EmitStatus(const StatusString &aString) const;
     void EmitStatus(const char *aFmt, ...) const OT_TOOL_PRINTF_STYLE_FORMAT_ARG_CHECK(2, 3);
+
+#if OPENTHREAD_FTD || OPENTHREAD_MTD
     void EmitCoapStatus(const char             *aAction,
                         const Coap::Message    &aMessage,
                         const Ip6::MessageInfo &aMessageInfo,
                         Error                  *aError = nullptr) const;
-
     void HandleNotifierEvents(Events aEvents) const;
+#endif
 };
 
 } // namespace Utils
 } // namespace ot
 
-#endif //(OPENTHREAD_MTD || OPENTHREAD_FTD) && OPENTHREAD_CONFIG_OTNS_ENABLE
+#endif // OPENTHREAD_CONFIG_OTNS_ENABLE
 
 #endif // UTILS_OTNS_HPP_