Show icons on dropdown menu on a layout

Question

I added a dropdown menu in a RelativeLayout but they don't show the icon, how can I fix it?

creating and showing the menu:

    final PopupMenu popup = new PopupMenu(context, dots);
    popup.getMenuInflater().inflate(R.menu.absences_menu, popup.getMenu());

    popup.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
        public boolean onMenuItemClick(MenuItem item) {
            Toast.makeText(context, "You Clicked : " + item.getTitle(), Toast.LENGTH_SHORT).show();
            return true;
        }
    });

    dots.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View view) {
            popup.show();
        }
    });

absences_menu.xml:

<menu xmlns:android="http://schemas.android.com/apk/res/android" >

<item
    android:id="@+id/absences_remove"
    android:title="Remove"
    android:icon="@drawable/delete"/>

<item
    android:id="@+id/two"
    android:title="Two"/>

<item
    android:id="@+id/three"
    android:title="Three"/>

</menu>

Result:

Question: How to add icons in a dynamic dropdown menu inside a RelativeLayout?