"Nicole and Keith Urban are delighted to announce that Nicole Kidman gave birth to a baby girl on yesterday morning in the United States," her agent, Allen Eichhorn, said in a statement.

The infant was delivered in the United States and weighed six pounds, seven and a half ounces (2.93 kilograms) at birth.

"Husband Keith was by Nicole's side, and mother and baby are very well," Eichhorn said.

Kidman, who won an Oscar in 2002 for her role in "The Hours," adopted a boy and a girl when she was married to Hollywood actor Tom Cruise.

Her first marriage lasted about 10 years from 1990 to 2001.

She married country music star, Grammy winner, Keith Urban, also an Australian citizens as her, in June 25, 2006.

"She's never been happier and healthier," a close family friend said. "She is absolutely radiant and enjoying nesting and homemaking with Keith at their new home in Nashville."