diff --git a/pkg/services/tree/service.go b/pkg/services/tree/service.go
index 7ab8fd13c..acce3f1e7 100644
--- a/pkg/services/tree/service.go
+++ b/pkg/services/tree/service.go
@@ -13,6 +13,7 @@ import (
 	cidSDK "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container/id"
 	netmapSDK "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/netmap"
 	"github.com/panjf2000/ants/v2"
+	"go.uber.org/atomic"
 	"go.uber.org/zap"
 )
 
@@ -31,6 +32,8 @@ type Service struct {
 	syncChan chan struct{}
 	syncPool *ants.Pool
 
+	initialSyncDone atomic.Bool
+
 	// cnrMap contains existing (used) container IDs.
 	cnrMap map[cidSDK.ID]struct{}
 	// cnrMapMtx protects cnrMap
@@ -89,6 +92,10 @@ func (s *Service) Shutdown() {
 }
 
 func (s *Service) Add(ctx context.Context, req *AddRequest) (*AddResponse, error) {
+	if !s.initialSyncDone.Load() {
+		return nil, ErrAlreadySyncing
+	}
+
 	b := req.GetBody()
 
 	var cid cidSDK.ID
@@ -137,6 +144,10 @@ func (s *Service) Add(ctx context.Context, req *AddRequest) (*AddResponse, error
 }
 
 func (s *Service) AddByPath(ctx context.Context, req *AddByPathRequest) (*AddByPathResponse, error) {
+	if !s.initialSyncDone.Load() {
+		return nil, ErrAlreadySyncing
+	}
+
 	b := req.GetBody()
 
 	var cid cidSDK.ID
@@ -197,6 +208,10 @@ func (s *Service) AddByPath(ctx context.Context, req *AddByPathRequest) (*AddByP
 }
 
 func (s *Service) Remove(ctx context.Context, req *RemoveRequest) (*RemoveResponse, error) {
+	if !s.initialSyncDone.Load() {
+		return nil, ErrAlreadySyncing
+	}
+
 	b := req.GetBody()
 
 	var cid cidSDK.ID
@@ -246,6 +261,10 @@ func (s *Service) Remove(ctx context.Context, req *RemoveRequest) (*RemoveRespon
 // Move applies client operation to the specified tree and pushes in queue
 // for replication on other nodes.
 func (s *Service) Move(ctx context.Context, req *MoveRequest) (*MoveResponse, error) {
+	if !s.initialSyncDone.Load() {
+		return nil, ErrAlreadySyncing
+	}
+
 	b := req.GetBody()
 
 	var cid cidSDK.ID
@@ -294,6 +313,10 @@ func (s *Service) Move(ctx context.Context, req *MoveRequest) (*MoveResponse, er
 }
 
 func (s *Service) GetNodeByPath(ctx context.Context, req *GetNodeByPathRequest) (*GetNodeByPathResponse, error) {
+	if !s.initialSyncDone.Load() {
+		return nil, ErrAlreadySyncing
+	}
+
 	b := req.GetBody()
 
 	var cid cidSDK.ID
@@ -370,6 +393,10 @@ func (s *Service) GetNodeByPath(ctx context.Context, req *GetNodeByPathRequest)
 }
 
 func (s *Service) GetSubTree(req *GetSubTreeRequest, srv TreeService_GetSubTreeServer) error {
+	if !s.initialSyncDone.Load() {
+		return ErrAlreadySyncing
+	}
+
 	b := req.GetBody()
 
 	var cid cidSDK.ID
@@ -499,6 +526,10 @@ func (s *Service) Apply(_ context.Context, req *ApplyRequest) (*ApplyResponse, e
 }
 
 func (s *Service) GetOpLog(req *GetOpLogRequest, srv TreeService_GetOpLogServer) error {
+	if !s.initialSyncDone.Load() {
+		return ErrAlreadySyncing
+	}
+
 	b := req.GetBody()
 
 	var cid cidSDK.ID
@@ -559,6 +590,10 @@ func (s *Service) GetOpLog(req *GetOpLogRequest, srv TreeService_GetOpLogServer)
 }
 
 func (s *Service) TreeList(ctx context.Context, req *TreeListRequest) (*TreeListResponse, error) {
+	if !s.initialSyncDone.Load() {
+		return nil, ErrAlreadySyncing
+	}
+
 	var cid cidSDK.ID
 
 	err := cid.Decode(req.GetBody().GetContainerId())
@@ -642,5 +677,9 @@ func (s *Service) getContainerInfo(cid cidSDK.ID, pub []byte) ([]netmapSDK.NodeI
 }
 
 func (s *Service) Healthcheck(context.Context, *HealthcheckRequest) (*HealthcheckResponse, error) {
+	if !s.initialSyncDone.Load() {
+		return nil, ErrAlreadySyncing
+	}
+
 	return new(HealthcheckResponse), nil
 }
diff --git a/pkg/services/tree/sync.go b/pkg/services/tree/sync.go
index 554d74091..ed87eac45 100644
--- a/pkg/services/tree/sync.go
+++ b/pkg/services/tree/sync.go
@@ -314,7 +314,7 @@ func (s *Service) syncLoop(ctx context.Context) {
 			cnrs, err := s.cfg.cnrSource.List()
 			if err != nil {
 				s.log.Error("could not fetch containers", zap.Error(err))
-				continue
+				break
 			}
 
 			newMap, cnrsToSync := s.containersToSync(cnrs)
@@ -325,6 +325,7 @@ func (s *Service) syncLoop(ctx context.Context) {
 
 			s.log.Debug("trees have been synchronized")
 		}
+		s.initialSyncDone.Store(true)
 	}
 }