Add a task from a different project in current project

User is a member of two projects.

Tasks assigned to user in project 1 apply to project 2 as well.

How can I "import" the task from project 1 to show in project 2's work breakdown? When I click on "Add Work Item", -> "Add Existing Work Item", it would seem that if I could select the other project from the Project Area box, that would work, however the Project Areas box only shows the current Project and does not allow me to select.  Do I need to create a cross-project dependency somehow?