Updated

Katy Perry apologized to her fans after announced she's pushing back the start of her new tour due to "unavoidable production delays."

The pop star's "Witness: The Tour" will now begin Sept. 19 in Montreal.

Perry wrote on Instagram Thursday that "major elements of my tour stage design could not be available for me to rehearse on until this week."

The tour was originally planned to kick off Sept. 7 in Columbus, Ohio.

"I'm sorry for any inconvenience this causes, but hope everyone who sees the show will agree it was worth the wait," she wrote.

Tickets purchased for the original concert dates will be honored at its new date. Refunds are also available at point of purchase.

The singer also announced that Carly Rae Jepsen, Noah Cyrus and Purity Ring will open for her on the road.

The Associated Press contributed to this report.