Grammy-winning R&B singer R. Kelly has undergone emergency throat surgery and will be unable to perform for an indefinite period

The 44 year-old Kelly, whose real name is Robert Kelly, was in severe pain and was rushed to a Chicago hospital on Tuesday where an abscess on one of his tonsils was drained, according to a statement from spokesman Allan Mayer.

Kelly just completed the U.S. leg of his worldwide "Love Letter" tour, but it was not known when he will be able to resume performing, said the statement.

In his last Tweet a week ago, Kelly wrote that he did not want to take any more medicine. "I feel like my throat is coming back. I've been in bed sweating like crazy. Thanks guys."

Kelly, whose hits include "You Remind Me of Something" and "I Believe I Can Fly," first gained fame in the early 1990s, and he enjoyed a solid career well into the 2000s.

In more recent years, however, Kelly's music career has often been eclipsed by legal troubles. In 2008, a Chicago jury acquitted him of child pornography charges, and recently court documents have shown him a year behind on mortgage payments for his multimillion-dollar mansion in suburban Chicago.