International superstar Beyonce has written a handwritten note apologizing to fans for scrapping a performance in Belgium on Tuesday.

The Single Ladies (Put a Ring On It) singer was advised to cancel the show in Antwerp on doctor's orders after suffering from dehydration and exhaustion, fuelling ongoing rumors she is expecting her second child with husband Jay-Z.

Now, Beyonce has uploaded a note to revelers left disappointed by the postponed show, and vowed to be back on stage at the Sportpaleis arena in Antwerp on Wednesday night.

A picture of the letter was posted on Facebook, and reads, "To my dearest fans in Antwerp. I've never postponed a show in my life. It was very hard for me. I promise I will make it up for you soon. I'm sorry if I disappointed you."

"Thank you for your concern. I am feeling much better now and am ready to give you a great show. See you tonight."

The axed show will be rescheduled at a later date.