How add options to a select with an AngularJS directive?

You can use directive from Angular JS:

Markup:

<div ng-controller="MainCtrl">
<select ng-model="country" ng-options="c.name for c in countries"></select>
{{country}}
</div>

Script:

app.controller('MainCtrl', function($scope) { 
   $scope.countries = [
    {name:'Vereinigte Arabische Emirate', value:'AE'},
    {name:'Andorra', value:'AD'},
  ];

  $scope.country = $scope.countries[1]; 

});

Check the docs of select: Angular Select

EDIT WITH DIRECTIVE

Directive:

  app.directive('sel', function () {
    return {
        template: '<select ng-model="selectedValue" ng-options="c.name for c in countries"></select>',
        restrict: 'E',
        scope: {
            selectedValue: '='
        },
        link: function (scope, elem, attrs) {
            scope.countries = [{
                name: 'Vereinigte Arabische Emirate',
                value: 'AE'
            }, {
                name: 'Andorra',
                value: 'AD'
            }, ];
            scope.selectedValue = scope.countries[1];
        }
    };
});

Main controller:

app.controller('MainCtrl', function($scope) {

  $scope.country={};

})

Markup:

<div ng-controller="MainCtrl">
<sel selected-value="country"></sel>
{{country}}
</div>

Working Example: EXAMPLE