BOSTON (CBS) – Aerosmith is cutting its South American tour short because of “unexpected medical issues” for lead singer Steven Tyler.

The rock star said in a statement Tuesday that he is expected to make a full recovery and hopes to perform again after “proper rest and treatment.”

READ MORE: First Widespread Snow Of The Season Expected Wednesday For Massachusetts

Tyler did not specify his medical problems but said in the statement that he flew back to the United States on a doctor’s orders Monday night after Aerosmith’s show in Sao Paulo, Brazil.

READ MORE: ESPN's Ryan Clark Compares Bill Belichick To ... God?

Steven Tyler performs in Sept. 2017 (Photo by Jonathan Leibson/Getty Images for Celebrity Fight Night)

“I am not in a life threatening condition, but I need to deal with this right away, and get some rest and medical care immediately in order to sustain and maintain my future performances,” Tyler said. “I promise I’ll be back. . . unfortunately health does not wait and it’s something even I can’t schedule around our shows.”

MORE NEWS: Bills' Jordan Poyer, Micah Hyde Get Mighty Offended When Asked If Pats Loss Was 'Embarrassing'

Tyler is 69 years old. Aerosmith originated in Boston in 1970.