Jessica Simpson [ tickets ], who was scheduled to close out 1999 with appearances at a series of radio festivals, has cancelled all of her remaining live performances through the end of the year due to "a serious upper respiratory infection," according to a statement released by the teen singer's camp.

She was to have performed in Philadelphia, Boston, New York, Los Angeles, Sacramento and Detroit. She was also scheduled to appear on the television talk show ''The View'' to promote her debut album for Columbia Records, ''Sweet Kisses.''

In the statement, Simpson apologized for disappointing her fans and promised to make up for the cancellations after the first of the year. She also addressed her bout with strep and the flu in diary entries posted on her official website.

Simpson recently wrapped up a stint as the opening act on Ricky Martin's North American tour. Her first single, ''I Wanna Love You Forever,'' is currently at No. 3 on Billboard's Hot 100 singles chart.