Lady Gaga, 2017

Lady Gaga performs during her 'Joanne' World Tour at Citi Field on Aug. 29, 2017 in New York City.

Kevin Mazur/Getty Images for Live Nation

Lady Gaga has postponed her Monday night (Sept. 4) concert in Montreal, the singer announced on Twitter. Gaga said she has been feeling ill since her recent tour stop at New York City's Citi Field, where she performed in the rain.

"To my beautiful fans," she wrote. "I couldn't be more devastated that I am unable to perform tonight. I sing this entire show live, and pride myself in giving it all, but when I sang in the rain at Citi Field I got sick and have been pushing through. I am so sorry to anyone who had their heart set on seeing me tonight. I love you. Xoxo, Joanne."

She then tweeted her plans to send free pizza to all the fans waiting outside her Montreal hotel Monday evening. "I love u so much & I'm so sorry u are the most loyal fans," she apologized.

A joint statement from Live Nation and Evenko was also released on Evenko's website: "Unfortunately tonight’s Lady Gaga Joanne World Tour Concert has been postponed. Hoping not to disappoint her fans, Lady Gaga took today to rest but unfortunately, has now been instructed by her doctor that she will need to reschedule this evening’s show due to respiratory infection and laryngitis."

A rescheduled date is in the works, and ticketholders have been told to hold onto their current tickets.

Gaga, who was set to play Montreal's Bell Centre before calling off the show, is currently on her Joanne World Tour. She has a pair of Toronto dates at the Air Canada Centre up next, on Sept. 6-7, before continuing on to Philadelphia.