Former U.S. leader Bill Clinton is set to become a grandfather - his daughter Chelsea is pregnant with her first child.

The former First Daughter, 34, made the big announcement during an event in New York City on Thursday (17Apr14).

Chelsea said, "Mark (Mezvinsky) and I are very excited that we have our first child arriving later this year... I just hope that I will be as good a mum to my child and hopefully children as my mum was to me."

Clinton and Mezvinsky wed in 2010.