Woocommerce: How to have deliveries to two specific cities only?

Hi WordPress people

I am doing some functionality research for a website I am going to be developing soon.

It will be an online florist in Dubai so I will be using Woocommerce as the shop. One of my clients many requests is to restrict the deliveries to only Dubai & Sharjah. So if/when the user tries to select another destination in the delivery address form it will either grey out or an error message will appear stating that deliveries are restricted to Dubai & Sharjah.

Many Thanks