diff --git a/lib/content_management/view/create_source_page.dart b/lib/content_management/view/create_source_page.dart
index 7487e05..d971a0c 100644
--- a/lib/content_management/view/create_source_page.dart
+++ b/lib/content_management/view/create_source_page.dart
@@ -166,6 +166,9 @@ class _CreateSourceViewState extends State<_CreateSourceView> {
                       decoration: InputDecoration(
                         labelText: l10n.language,
                         border: const OutlineInputBorder(),
+                        helperText: state.languagesIsLoadingMore
+                            ? l10n.loadingFullList
+                            : null,
                       ),
                       items: [
                         DropdownMenuItem(value: null, child: Text(l10n.none)),
@@ -176,9 +179,11 @@ class _CreateSourceViewState extends State<_CreateSourceView> {
                           ),
                         ),
                       ],
-                      onChanged: (value) => context
-                          .read<CreateSourceBloc>()
-                          .add(CreateSourceLanguageChanged(value)),
+                      onChanged: state.languagesIsLoadingMore
+                          ? null
+                          : (value) => context
+                              .read<CreateSourceBloc>()
+                              .add(CreateSourceLanguageChanged(value)),
                     ),
                     const SizedBox(height: AppSpacing.lg),
                     DropdownButtonFormField<SourceType?>(
@@ -206,6 +211,9 @@ class _CreateSourceViewState extends State<_CreateSourceView> {
                       decoration: InputDecoration(
                         labelText: l10n.headquarters,
                         border: const OutlineInputBorder(),
+                        helperText: state.countriesIsLoadingMore
+                            ? l10n.loadingFullList
+                            : null,
                       ),
                       items: [
                         DropdownMenuItem(value: null, child: Text(l10n.none)),
@@ -232,9 +240,11 @@ class _CreateSourceViewState extends State<_CreateSourceView> {
                           ),
                         ),
                       ],
-                      onChanged: (value) => context
-                          .read<CreateSourceBloc>()
-                          .add(CreateSourceHeadquartersChanged(value)),
+                      onChanged: state.countriesIsLoadingMore
+                          ? null
+                          : (value) => context
+                              .read<CreateSourceBloc>()
+                              .add(CreateSourceHeadquartersChanged(value)),
                     ),
                     const SizedBox(height: AppSpacing.lg),
                     DropdownButtonFormField<ContentStatus>(
diff --git a/lib/content_management/view/edit_headline_page.dart b/lib/content_management/view/edit_headline_page.dart
index bd92f72..42fb440 100644
--- a/lib/content_management/view/edit_headline_page.dart
+++ b/lib/content_management/view/edit_headline_page.dart
@@ -287,6 +287,9 @@ class _EditHeadlineViewState extends State<_EditHeadlineView> {
                       decoration: InputDecoration(
                         labelText: l10n.countryName,
                         border: const OutlineInputBorder(),
+                        helperText: state.countriesIsLoadingMore
+                            ? l10n.loadingFullList
+                            : null,
                       ),
                       items: [
                         DropdownMenuItem(value: null, child: Text(l10n.none)),
@@ -313,9 +316,11 @@ class _EditHeadlineViewState extends State<_EditHeadlineView> {
                           ),
                         ),
                       ],
-                      onChanged: (value) => context
-                          .read<EditHeadlineBloc>()
-                          .add(EditHeadlineCountryChanged(value)),
+                      onChanged: state.countriesIsLoadingMore
+                          ? null
+                          : (value) => context
+                              .read<EditHeadlineBloc>()
+                              .add(EditHeadlineCountryChanged(value)),
                     ),
                     const SizedBox(height: AppSpacing.lg),
                     DropdownButtonFormField<ContentStatus>(
diff --git a/lib/content_management/view/edit_source_page.dart b/lib/content_management/view/edit_source_page.dart
index edb25a4..7cc0473 100644
--- a/lib/content_management/view/edit_source_page.dart
+++ b/lib/content_management/view/edit_source_page.dart
@@ -196,6 +196,9 @@ class _EditSourceViewState extends State<_EditSourceView> {
                       decoration: InputDecoration(
                         labelText: l10n.language,
                         border: const OutlineInputBorder(),
+                        helperText: state.languagesIsLoadingMore
+                            ? l10n.loadingFullList
+                            : null,
                       ),
                       items: [
                         DropdownMenuItem(value: null, child: Text(l10n.none)),
@@ -206,9 +209,11 @@ class _EditSourceViewState extends State<_EditSourceView> {
                           ),
                         ),
                       ],
-                      onChanged: (value) => context
-                          .read<EditSourceBloc>()
-                          .add(EditSourceLanguageChanged(value)),
+                      onChanged: state.languagesIsLoadingMore
+                          ? null
+                          : (value) => context
+                              .read<EditSourceBloc>()
+                              .add(EditSourceLanguageChanged(value)),
                     ),
                     const SizedBox(height: AppSpacing.lg),
                     DropdownButtonFormField<SourceType?>(
@@ -236,6 +241,9 @@ class _EditSourceViewState extends State<_EditSourceView> {
                       decoration: InputDecoration(
                         labelText: l10n.headquarters,
                         border: const OutlineInputBorder(),
+                        helperText: state.countriesIsLoadingMore
+                            ? l10n.loadingFullList
+                            : null,
                       ),
                       items: [
                         DropdownMenuItem(value: null, child: Text(l10n.none)),
@@ -262,9 +270,11 @@ class _EditSourceViewState extends State<_EditSourceView> {
                           ),
                         ),
                       ],
-                      onChanged: (value) => context
-                          .read<EditSourceBloc>()
-                          .add(EditSourceHeadquartersChanged(value)),
+                      onChanged: state.countriesIsLoadingMore
+                          ? null
+                          : (value) => context
+                              .read<EditSourceBloc>()
+                              .add(EditSourceHeadquartersChanged(value)),
                     ),
                     const SizedBox(height: AppSpacing.lg),
                     DropdownButtonFormField<ContentStatus>(
diff --git a/lib/l10n/app_localizations.dart b/lib/l10n/app_localizations.dart
index b88c8ce..ef0eb1f 100644
--- a/lib/l10n/app_localizations.dart
+++ b/lib/l10n/app_localizations.dart
@@ -1328,6 +1328,12 @@ abstract class AppLocalizations {
   /// **'Loading data...'**
   String get loadingData;
 
+  /// Message displayed in a dropdown when its full list of items is being loaded in the background.
+  ///
+  /// In en, this message translates to:
+  /// **'Loading full list...'**
+  String get loadingFullList;
+
   /// Title for the Create Source page
   ///
   /// In en, this message translates to:
diff --git a/lib/l10n/app_localizations_ar.dart b/lib/l10n/app_localizations_ar.dart
index 04471a0..9aaa4b2 100644
--- a/lib/l10n/app_localizations_ar.dart
+++ b/lib/l10n/app_localizations_ar.dart
@@ -696,6 +696,9 @@ class AppLocalizationsAr extends AppLocalizations {
   @override
   String get loadingData => 'جاري تحميل البيانات...';
 
+  @override
+  String get loadingFullList => 'جاري تحميل القائمة الكاملة...';
+
   @override
   String get createSource => 'إنشاء مصدر';
 
diff --git a/lib/l10n/app_localizations_en.dart b/lib/l10n/app_localizations_en.dart
index 462f47e..d905389 100644
--- a/lib/l10n/app_localizations_en.dart
+++ b/lib/l10n/app_localizations_en.dart
@@ -695,6 +695,9 @@ class AppLocalizationsEn extends AppLocalizations {
   @override
   String get loadingData => 'Loading data...';
 
+  @override
+  String get loadingFullList => 'Loading full list...';
+
   @override
   String get createSource => 'Create Source';
 
diff --git a/lib/l10n/arb/app_ar.arb b/lib/l10n/arb/app_ar.arb
index 95552bf..795602d 100644
--- a/lib/l10n/arb/app_ar.arb
+++ b/lib/l10n/arb/app_ar.arb
@@ -854,6 +854,10 @@
   "@loadingData": {
     "description": "رسالة عامة تُعرض أثناء تحميل البيانات لنموذج"
   },
+  "loadingFullList": "جاري تحميل القائمة الكاملة...",
+  "@loadingFullList": {
+    "description": "رسالة تُعرض في قائمة منسدلة عند تحميل قائمتها الكاملة من العناصر في الخلفية."
+  },
   "createSource": "إنشاء مصدر",
   "@createSource": {
     "description": "عنوان صفحة إنشاء مصدر"
@@ -1090,4 +1094,4 @@
   "@countryPickerSelectCountryLabel": {
     "description": "التسمية المعروضة عند عدم اختيار أي دولة في حقل نموذج منتقي البلد"
   }
-}
\ No newline at end of file
+}
diff --git a/lib/l10n/arb/app_en.arb b/lib/l10n/arb/app_en.arb
index 3192882..330be9d 100644
--- a/lib/l10n/arb/app_en.arb
+++ b/lib/l10n/arb/app_en.arb
@@ -854,6 +854,10 @@
   "@loadingData": {
     "description": "Generic message displayed while loading data for a form"
   },
+  "loadingFullList": "Loading full list...",
+  "@loadingFullList": {
+    "description": "Message displayed in a dropdown when its full list of items is being loaded in the background."
+  },
   "createSource": "Create Source",
   "@createSource": {
     "description": "Title for the Create Source page"