How to Interrupt the UI thread

I'm working on a simulation model that iterates over time steps. At times when the model results start to go South, I want to be able to click on a button to halt the iteration. However, if my testing is correct, when the iteration is running in the UI thread, the Button.Click event is not actuated because the thread is busy iterating. Is that correct? Is there a way to interrupt the UI thread with a button click when the thread is really busy?

One way to handle this problem is to create a Task using the Task Parallel Library to do the computationally-heavy iterations. I'm starting to work on this approach in case there is no way to interrupt the UI thread but I thought I'd check here to make sure I'm not missing a simpler approach.