Jennifer Lopez says that she knows Beyonc Knowles will be a "great mom."

The 42-year-old performer added to the inundation of celebrity well wishers giving their congratulations to the Single Ladies singer and husband Jay-Z who welcomed their daughter Blue Ivy Carter to the world over the weekend.

Jennifer, who gave birth to twins Max and Emme nearly three years ago, told Entertainment Tonight that Beyonc has a lot of wonderful things to look forward to.

"The best part of Beyonc's life is about to begin," Jennifer said with a smile. "I wish her the best. I know she's going to love it and be a great mom."

The American Idol judge also put paid to rumours that host of the talent show Ryan Seacrest was leaving the hit show.

"Is he going somewhere?" Jennifer asked which was followed up with a resolute answer from her fellow judge Randy Jackson.

"Seacrest ain't going nowhere," Randy said adding that the show returns, with Seacrest as host, on January 18.