The 'Sex on Fire' band were forced to finish a show early in Dallas on Friday after the frontman stormed offfstage to "vomit" and "drink a beer". The group later announced plans to reschedule two shows in Texas in September.
However, a representative for the band has now issued a statement, saying that they are "devastated" to be cancelling their tour in order for Caleb to recover, according to TMZ.
"We are so sorry to say Kings of Leon are cancelling their entire US tour due to Caleb Followill suffering from vocal issues and exhaustion," the statement read.
"The band is devastated, but in order to give their fans the shows they deserve, they need to take this break. Unfortunately, the US dates cannot be rescheduled due to the band's international tour schedule."
Tickets for the cancelled shows will be refunded, with the band continuing to tour in Canada on September 28.
Earlier, Caleb's brother Jared Followill tweeted: "I love our fans so much. I know you guys aren't stupid. I can't lie. There are problems in our band bigger than not drinking enough Gatorade."
Drummer and brother Nathan Followill also wrote: "Not so good morning for me today. Ashamed & embarrassed by last night's fiasco. Can't apologise enough, utterly gutted. A million I'm sorry's."
Watch the video for Kings of Leon's 2004 single 'The Bucket' below: