Region field visible for Country when "Allow to Choose State if It is Optional for Country" is disabled

app/code/Magento/Ui/view/base/web/js/form/element/region.js

@@ -23,6 +23,22 @@ define([
             }
         },
 
+        /**
+         * {@inheritdoc}
+         */
+        initialize: function () {
+            var option;
+
+            this._super();
+
+            option = _.find(this.countryOptions, function (row) {
+                return row['is_default'] === true;
+            });
+            this.hideRegion(option);
+
+            return this;
+        },
+
         /**
          * Method called every time country selector's value gets changed.
          * Updates all validations and requirements for certain country.
@@ -42,16 +58,9 @@ define([
                 return;
             }
 
-            defaultPostCodeResolver.setUseDefaultPostCode(!option['is_zipcode_optional']);
-
-            if (option['is_region_visible'] === false) {
-                // Hide select and corresponding text input field if region must not be shown for selected country.
-                this.setVisible(false);
+            this.hideRegion(option);
 
-                if (this.customEntry) { // eslint-disable-line max-depth
-                    this.toggleInput(false);
-                }
-            }
+            defaultPostCodeResolver.setUseDefaultPostCode(!option['is_zipcode_optional']);
 
             isRegionRequired = !this.skipValidation && !!option['is_region_required'];
 
@@ -67,7 +76,24 @@ define([
                 input.validation['required-entry'] = isRegionRequired;
                 input.validation['validate-not-number-first'] = !this.options().length;
             }.bind(this));
+        },
+
+        /**
+         * Hide select and corresponding text input field if region must not be shown for selected country.
+         *
+         * @private
+         * @param {Object}option
+         */
+        hideRegion: function (option) {
+            if (!option || option['is_region_visible'] !== false) {
+                return;
+            }
+
+            this.setVisible(false);
+
+            if (this.customEntry) {
+                this.toggleInput(false);
+            }
         }
     });
 });
-

dev/tests/js/jasmine/tests/app/code/Magento/Ui/base/js/form/element/region.test.js

@@ -47,6 +47,40 @@ define([
             });
         });
 
+        describe('initialize method', function () {
+            it('Hides region field when it should be hidden for default country', function () {
+                model.countryOptions = {
+                    'DefaultCountryCode': {
+                        'is_default': true,
+                        'is_region_visible': false
+                    },
+                    'NonDefaultCountryCode': {
+                        'is_region_visible': true
+                    }
+                };
+
+                model.initialize();
+
+                expect(model.visible()).toEqual(false);
+            });
+
+            it('Shows region field when it should be visible for default country', function () {
+                model.countryOptions = {
+                    'CountryCode': {
+                        'is_default': true,
+                        'is_region_visible': true
+                    },
+                    'NonDefaultCountryCode': {
+                        'is_region_visible': false
+                    }
+                };
+
+                model.initialize();
+
+                expect(model.visible()).toEqual(true);
+            });
+        });
+
         describe('update method', function () {
             it('makes field optional when there is no corresponding country', function () {
                 var value = 'Value';