Constantly Update UI in Java FX worker thread

I have Label label in my FXML Application.

I want this label to change once a second. Currently I use this:

        Task task = new Task<Void>() {
        @Override
        public Void call() throws Exception {
            int i = 0;
            while (true) {
                lbl_tokenValid.setText(""+i);
                i++;
                Thread.sleep(1000);
            }
        }
    };
    Thread th = new Thread(task);
    th.setDaemon(true);
    th.start();

However nothing is happening.

I don't get any errors or exceptions. I don't need the value I change the label to in my main GUI thread so I don't see the point in the updateMessage or updateProgress methods.

What is wrong?