The "Desktop Mouse Click" action will trigger attached to the drop-down events.
It there is a need to workaround this approach it is possible to trigger the events attached to the drop-down set of elements. Then it will be necessary to know to which element the appropriate event is attached. The fastest way to check the events is to inspect the elements in Firefox as shown on the attached screen-shot.
Then you can add this DOM element in the elements repository using elements menu
To open the drop-down it is necessary to trigger OnMouseDown event and to select country - OnMouseUp. Please, refer to the attached test script for further clarification.
I hope these pointers are useful to you.