Country-pop singer Taylor Swift on Wednesday canceled three more of her US concerts due to bronchitis but said she hoped to be better for a July 14 date in Montreal.

Swift, 21, said she was advised by doctors not to perform at all this week. She postponed dates in Charlotte and Atlanta on July 8, 9 and 10 for October and November, after pulling out of a show in Louisville on July 2.

It's the first time that Swift has had to postpone or cancel a show because of illness.

"It breaks my heart to miss out on this weekend's shows with my friends in Charlotte and Atlanta," Swift said in a statement.

"I would never cancel if I thought I was physically able in the slightest to perform these shows. I am so sorry to the fans, but I look forward to seeing you when we come back through your towns, which we will do," she noted.