diff --git a/icu4c/source/common/unicode/platform.h b/icu4c/source/common/unicode/platform.h
index 7aca76c67db8..d0d87202f36a 100644
--- a/icu4c/source/common/unicode/platform.h
+++ b/icu4c/source/common/unicode/platform.h
@@ -217,6 +217,16 @@
 #   define U_REAL_MSVC
 #endif
 
+/**
+ * \def U_CLANG_CL
+ * Defined if the compiler is Clang compatible with MSVC (Clang on Windows).
+ * Otherwise undefined.
+ * @internal
+ */
+#if (defined(_MSC_VER) && defined(__clang__) && __clang__)
+#   define U_CLANG_CL
+#endif
+
 /**
  * \def CYGWINMSVC
  * Defined if this is Windows with Cygwin, but using MSVC rather than gcc.
@@ -235,7 +245,7 @@
 /**
  * \def U_PLATFORM_USES_ONLY_WIN32_API
  * Defines whether the platform uses only the Win32 API.
- * Set to 1 for Windows/MSVC and MinGW but not Cygwin.
+ * Set to 1 for Windows/MSVC, ClangCL and MinGW but not Cygwin.
  * @internal
  */
 #ifdef U_PLATFORM_USES_ONLY_WIN32_API
@@ -250,7 +260,7 @@
 /**
  * \def U_PLATFORM_HAS_WIN32_API
  * Defines whether the Win32 API is available on the platform.
- * Set to 1 for Windows/MSVC, MinGW and Cygwin.
+ * Set to 1 for Windows/MSVC, ClangCL, MinGW and Cygwin.
  * @internal
  */
 #ifdef U_PLATFORM_HAS_WIN32_API
diff --git a/icu4c/source/tools/genccode/genccode.c b/icu4c/source/tools/genccode/genccode.c
index 388317a0634d..f79c2b51cd3d 100644
--- a/icu4c/source/tools/genccode/genccode.c
+++ b/icu4c/source/tools/genccode/genccode.c
@@ -70,7 +70,9 @@ enum {
 #ifdef CAN_GENERATE_OBJECTS
   kOptObject,
   kOptMatchArch,
+#ifdef U_CLANG_CL
   kOptCpuArch,
+#endif
   kOptSkipDllExport,
 #endif
   kOptFilename,
@@ -87,7 +89,9 @@ static UOption options[]={
 #ifdef CAN_GENERATE_OBJECTS
 /*6*/UOPTION_DEF("object", 'o', UOPT_NO_ARG),
      UOPTION_DEF("match-arch", 'm', UOPT_REQUIRES_ARG),
+#ifdef U_CLANG_CL
      UOPTION_DEF("cpu-arch", 'c', UOPT_REQUIRES_ARG),
+#endif
      UOPTION_DEF("skip-dll-export", '\0', UOPT_NO_ARG),
 #endif
      UOPTION_DEF("filename", 'f', UOPT_REQUIRES_ARG),
@@ -133,7 +137,9 @@ main(int argc, char* argv[]) {
             "\t-o or --object      write a .obj file instead of .c\n"
             "\t-m or --match-arch file.o  match the architecture (CPU, 32/64 bits) of the specified .o\n"
             "\t                    ELF format defaults to i386. Windows defaults to the native platform.\n"
+#ifdef U_CLANG_CL
             "\t-c or --cpu-arch    Specify a CPU architecture for which to write a .obj file for ClangCL on Windows\n"
+#endif
             "\t--skip-dll-export   Don't export the ICU data entry point symbol (for use when statically linking)\n");
 #endif
         fprintf(stderr,
@@ -199,7 +205,11 @@ main(int argc, char* argv[]) {
                 writeObjectCode(filename, options[kOptDestDir].value,
                                 options[kOptEntryPoint].doesOccur ? options[kOptEntryPoint].value : NULL,
                                 options[kOptMatchArch].doesOccur ? options[kOptMatchArch].value : NULL,
+#ifdef U_CLANG_CL
                                 options[kOptCpuArch].doesOccur ? options[kOptCpuArch].value : NULL,
+#else
+                                NULL,
+#endif
                                 options[kOptFilename].doesOccur ? options[kOptFilename].value : NULL,
                                 NULL,
                                 0,
diff --git a/icu4c/source/tools/toolutil/pkg_genc.cpp b/icu4c/source/tools/toolutil/pkg_genc.cpp
index 438552ab32ea..69bd5d30254c 100644
--- a/icu4c/source/tools/toolutil/pkg_genc.cpp
+++ b/icu4c/source/tools/toolutil/pkg_genc.cpp
@@ -858,14 +858,17 @@ getArchitecture(
         // this would potentially be problematic when cross-compiling as this code
         // would most likely be ran on host machine to generate the .obj file for
         // the target architecture.
-#       if defined(__clang__)
+#       ifdef U_CLANG_CL
             if (strcmp(optCpuArch, "x64") == 0) {
                 *pCPU = IMAGE_FILE_MACHINE_AMD64;
+            } else if (strcmp(optCpuArch, "x86") == 0) {
+                *pCPU = IMAGE_FILE_MACHINE_I386;
             } else if (strcmp(optCpuArch, "arm64") == 0) {
                 *pCPU = IMAGE_FILE_MACHINE_ARM64;
             } else {
                 // This should never happen.
-                *pCPU = IMAGE_FILE_MACHINE_UNKNOWN;
+                fprintf(stderr, "genccode: unable to process %s CPU architecture\n", optCpuArch);
+                exit(U_ILLEGAL_ARGUMENT_ERROR);
             }
 #       else
             *pCPU = IMAGE_FILE_MACHINE_UNKNOWN;