diff --git a/icu4c/source/common/uassert.h b/icu4c/source/common/uassert.h
index 0a6080db56..de1b393389 100644
--- a/icu4c/source/common/uassert.h
+++ b/icu4c/source/common/uassert.h
@@ -21,8 +21,12 @@
 #define U_ASSERT_H
 /* utypes.h is included to get the proper define for uint8_t */
 #include "unicode/utypes.h"
+#if U_RELEASE
+#define U_ASSERT(exp)
+#else
 #include <assert.h>
 #define U_ASSERT(exp) assert(exp)
 #endif
+#endif
 
 
diff --git a/icu4c/source/common/unicode/platform.h.in b/icu4c/source/common/unicode/platform.h.in
index 1b43d655d4..eff00568c7 100644
--- a/icu4c/source/common/unicode/platform.h.in
+++ b/icu4c/source/common/unicode/platform.h.in
@@ -44,6 +44,14 @@
 #define U_IOSTREAM_SOURCE @U_IOSTREAM_SOURCE@
 #endif
 
+#ifndef U_DEBUG
+#define U_DEBUG @ENABLE_DEBUG@
+#endif
+
+#ifndef U_RELEASE
+#define U_RELEASE @ENABLE_RELEASE@
+#endif
+
 /* Determines whether specific types are available */
 #ifndef U_HAVE_INT8_T
 #define U_HAVE_INT8_T @HAVE_INT8_T@
@@ -264,4 +272,3 @@ typedef unsigned short uint16_t;
 /*===========================================================================*/
 
 #define U_MAKE  "@U_MAKE@"
-
diff --git a/icu4c/source/common/unicode/pwin32.h b/icu4c/source/common/unicode/pwin32.h
index 1f33a975e1..730b461d13 100644
--- a/icu4c/source/common/unicode/pwin32.h
+++ b/icu4c/source/common/unicode/pwin32.h
@@ -42,6 +42,21 @@
 #define U_IOSTREAM_SOURCE 199711
 #endif
 
+#ifndef U_DEBUG
+#ifdef _DEBUG
+#define U_DEBUG 1
+#else
+#define U_DEBUG 0
+#endif
+
+#ifndef U_RELEASE
+#ifdef NDEBUG
+#define U_RELEASE 1
+#else
+#define U_RELEASE 0
+#endif
+#endif
+
 /* Determines whether specific types are available */
 #define U_HAVE_INT8_T 0
 #define U_HAVE_UINT8_T 0