diff --git a/goldens/public-api/angular/build/index.api.md b/goldens/public-api/angular/build/index.api.md
index 31576f664e36..aa9ac693864e 100644
--- a/goldens/public-api/angular/build/index.api.md
+++ b/goldens/public-api/angular/build/index.api.md
@@ -158,6 +158,7 @@ export function executeNgPackagrBuilder(options: NgPackagrBuilderOptions, contex
 export type ExtractI18nBuilderOptions = {
     buildTarget?: string;
     format?: Format;
+    i18nDuplicateTranslation?: I18NDuplicateTranslation;
     outFile?: string;
     outputPath?: string;
     progress?: boolean;
diff --git a/goldens/public-api/angular_devkit/build_angular/index.api.md b/goldens/public-api/angular_devkit/build_angular/index.api.md
index 9208d1ad56a1..cb46b4458351 100644
--- a/goldens/public-api/angular_devkit/build_angular/index.api.md
+++ b/goldens/public-api/angular_devkit/build_angular/index.api.md
@@ -191,6 +191,7 @@ export type ExecutionTransformer<T> = (input: T) => T | Promise<T>;
 export type ExtractI18nBuilderOptions = {
     buildTarget?: string;
     format?: Format;
+    i18nDuplicateTranslation?: I18NDuplicateTranslation;
     outFile?: string;
     outputPath?: string;
     progress?: boolean;
diff --git a/packages/angular/build/src/builders/extract-i18n/builder.ts b/packages/angular/build/src/builders/extract-i18n/builder.ts
index 5e44c31fa516..15b0156f749b 100644
--- a/packages/angular/build/src/builders/extract-i18n/builder.ts
+++ b/packages/angular/build/src/builders/extract-i18n/builder.ts
@@ -90,16 +90,23 @@ export async function execute(
       return path.relative(from, to);
     },
   };
+  const duplicateTranslationBehavior = normalizedOptions.i18nOptions.duplicateTranslationBehavior;
   const diagnostics = checkDuplicateMessages(
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
     checkFileSystem as any,
     extractionResult.messages,
-    normalizedOptions.i18nOptions.i18nDuplicateTranslation || 'warning',
+    duplicateTranslationBehavior,
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
     extractionResult.basePath as any,
   );
-  if (diagnostics.messages.length > 0) {
-    context.logger.warn(diagnostics.formatDiagnostics(''));
+  if (diagnostics.messages.length > 0 && duplicateTranslationBehavior !== 'ignore') {
+    if (duplicateTranslationBehavior === 'error') {
+      context.logger.error(`Extraction Failed: ${diagnostics.formatDiagnostics('')}`);
+
+      return { success: false };
+    } else {
+      context.logger.warn(diagnostics.formatDiagnostics(''));
+    }
   }
 
   // Serialize all extracted messages
diff --git a/packages/angular/build/src/builders/extract-i18n/options.ts b/packages/angular/build/src/builders/extract-i18n/options.ts
index 24be86ee7c8f..2904a466bd60 100644
--- a/packages/angular/build/src/builders/extract-i18n/options.ts
+++ b/packages/angular/build/src/builders/extract-i18n/options.ts
@@ -6,10 +6,11 @@
  * found in the LICENSE file at https://angular.dev/license
  */
 
+import { type DiagnosticHandlingStrategy } from '@angular/localize/tools';
 import { BuilderContext, targetFromTargetString } from '@angular-devkit/architect';
 import { fail } from 'node:assert';
 import path from 'node:path';
-import { createI18nOptions } from '../../utils/i18n-options';
+import { type I18nOptions, createI18nOptions } from '../../utils/i18n-options';
 import { Schema as ExtractI18nOptions, Format } from './schema';
 
 export type NormalizedExtractI18nOptions = Awaited<ReturnType<typeof normalizeOptions>>;
@@ -36,7 +37,12 @@ export async function normalizeOptions(
   // Target specifier defaults to the current project's build target with no specified configuration
   const buildTargetSpecifier = options.buildTarget ?? ':';
   const buildTarget = targetFromTargetString(buildTargetSpecifier, projectName, 'build');
-  const i18nOptions = createI18nOptions(projectMetadata, /** inline */ false, context.logger);
+  const i18nOptions: I18nOptions & {
+    duplicateTranslationBehavior: DiagnosticHandlingStrategy;
+  } = {
+    ...createI18nOptions(projectMetadata, /** inline */ false, context.logger),
+    duplicateTranslationBehavior: options.i18nDuplicateTranslation || 'warning',
+  };
 
   // Normalize xliff format extensions
   let format = options.format;
diff --git a/packages/angular/build/src/builders/extract-i18n/schema.json b/packages/angular/build/src/builders/extract-i18n/schema.json
index 9ab939b0e938..08a118ad7d5e 100644
--- a/packages/angular/build/src/builders/extract-i18n/schema.json
+++ b/packages/angular/build/src/builders/extract-i18n/schema.json
@@ -27,6 +27,11 @@
     "outFile": {
       "type": "string",
       "description": "Name of the file to output."
+    },
+    "i18nDuplicateTranslation": {
+      "type": "string",
+      "description": "How to handle duplicate translations.",
+      "enum": ["error", "warning", "ignore"]
     }
   },
   "additionalProperties": false
diff --git a/packages/angular/build/src/utils/i18n-options.ts b/packages/angular/build/src/utils/i18n-options.ts
index 53e5aca4d540..822683bef03d 100644
--- a/packages/angular/build/src/utils/i18n-options.ts
+++ b/packages/angular/build/src/utils/i18n-options.ts
@@ -6,7 +6,6 @@
  * found in the LICENSE file at https://angular.dev/license
  */
 
-import { DiagnosticHandlingStrategy } from '@angular/localize/tools';
 import path from 'node:path';
 import type { TranslationLoader } from './load-translations';
 
@@ -29,7 +28,6 @@ export interface I18nOptions {
   flatOutput?: boolean;
   readonly shouldInline: boolean;
   hasDefinedSourceLocale?: boolean;
-  i18nDuplicateTranslation?: DiagnosticHandlingStrategy;
 }
 
 function normalizeTranslationFileOption(
diff --git a/packages/angular_devkit/build_angular/src/builders/extract-i18n/builder.ts b/packages/angular_devkit/build_angular/src/builders/extract-i18n/builder.ts
index bb6750189a1a..2d22fda36e96 100644
--- a/packages/angular_devkit/build_angular/src/builders/extract-i18n/builder.ts
+++ b/packages/angular_devkit/build_angular/src/builders/extract-i18n/builder.ts
@@ -110,16 +110,23 @@ export async function execute(
       return path.relative(from, to);
     },
   };
+  const duplicateTranslationBehavior = normalizedOptions.i18nOptions.duplicateTranslationBehavior;
   const diagnostics = checkDuplicateMessages(
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
     checkFileSystem as any,
     extractionResult.messages,
-    'warning',
+    duplicateTranslationBehavior,
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
     extractionResult.basePath as any,
   );
-  if (diagnostics.messages.length > 0) {
-    context.logger.warn(diagnostics.formatDiagnostics(''));
+  if (diagnostics.messages.length > 0 && duplicateTranslationBehavior !== 'ignore') {
+    if (duplicateTranslationBehavior === 'error') {
+      context.logger.error(`Extraction Failed: ${diagnostics.formatDiagnostics('')}`);
+
+      return { success: false };
+    } else {
+      context.logger.warn(diagnostics.formatDiagnostics(''));
+    }
   }
 
   // Serialize all extracted messages
diff --git a/packages/angular_devkit/build_angular/src/builders/extract-i18n/options.ts b/packages/angular_devkit/build_angular/src/builders/extract-i18n/options.ts
index 492909da14f0..0aaf255e7d47 100644
--- a/packages/angular_devkit/build_angular/src/builders/extract-i18n/options.ts
+++ b/packages/angular_devkit/build_angular/src/builders/extract-i18n/options.ts
@@ -6,7 +6,8 @@
  * found in the LICENSE file at https://angular.dev/license
  */
 
-import { createI18nOptions } from '@angular/build/private';
+import { type I18nOptions, createI18nOptions } from '@angular/build/private';
+import { type DiagnosticHandlingStrategy } from '@angular/localize/tools';
 import { BuilderContext, targetFromTargetString } from '@angular-devkit/architect';
 import { fail } from 'node:assert';
 import path from 'node:path';
@@ -36,7 +37,12 @@ export async function normalizeOptions(
   // Target specifier defaults to the current project's build target with no specified configuration
   const buildTargetSpecifier = options.buildTarget ?? ':';
   const buildTarget = targetFromTargetString(buildTargetSpecifier, projectName, 'build');
-  const i18nOptions = createI18nOptions(projectMetadata, /** inline */ false, context.logger);
+  const i18nOptions: I18nOptions & {
+    duplicateTranslationBehavior: DiagnosticHandlingStrategy;
+  } = {
+    ...createI18nOptions(projectMetadata, /** inline */ false, context.logger),
+    duplicateTranslationBehavior: options.i18nDuplicateTranslation || 'warning',
+  };
 
   // Normalize xliff format extensions
   let format = options.format;
diff --git a/packages/angular_devkit/build_angular/src/builders/extract-i18n/schema.json b/packages/angular_devkit/build_angular/src/builders/extract-i18n/schema.json
index 9ab939b0e938..08a118ad7d5e 100644
--- a/packages/angular_devkit/build_angular/src/builders/extract-i18n/schema.json
+++ b/packages/angular_devkit/build_angular/src/builders/extract-i18n/schema.json
@@ -27,6 +27,11 @@
     "outFile": {
       "type": "string",
       "description": "Name of the file to output."
+    },
+    "i18nDuplicateTranslation": {
+      "type": "string",
+      "description": "How to handle duplicate translations.",
+      "enum": ["error", "warning", "ignore"]
     }
   },
   "additionalProperties": false
diff --git a/packages/angular_devkit/build_angular/src/builders/extract-i18n/works_spec.ts b/packages/angular_devkit/build_angular/src/builders/extract-i18n/works_spec.ts
index b0705dfee1b8..1f29fb96a581 100644
--- a/packages/angular_devkit/build_angular/src/builders/extract-i18n/works_spec.ts
+++ b/packages/angular_devkit/build_angular/src/builders/extract-i18n/works_spec.ts
@@ -147,6 +147,34 @@ describe('Extract i18n Target', () => {
     expect(fullLog).toContain('Duplicate messages with id');
   });
 
+  it('issues errors for duplicate message identifiers', async () => {
+    host.appendToFile(
+      'src/app/app.component.ts',
+      'const c = $localize`:@@message-2:message contents`; const d = $localize`:@@message-2:different message contents`;',
+    );
+
+    const logger = new logging.Logger('');
+    const logs: string[] = [];
+    logger.subscribe((e) => logs.push(e.message));
+
+    const run = await architect.scheduleTarget(
+      extractI18nTargetSpec,
+      {
+        i18nDuplicateTranslation: 'error',
+      },
+      { logger },
+    );
+    await expectAsync(run.result).toBeResolvedTo(jasmine.objectContaining({ success: false }));
+
+    await run.stop();
+
+    expect(host.scopedSync().exists(extractionFile)).toBe(false);
+
+    const fullLog = logs.join();
+    expect(fullLog).toContain('Duplicate messages with id');
+    expect(fullLog).toContain('Extraction Failed');
+  });
+
   it('ignores inline styles', async () => {
     host.appendToFile('src/app/app.component.html', '<p i18n>i18n test</p>');
     host.replaceInFile('src/app/app.component.ts', 'styleUrls', 'styles');