Prince William has broken his silence about the birth of his first child on Monday (22Jul13), insisting he and wife Catherine, Duchess Of Cambridge "could not be happier" following the arrival of their son. The baby boy, who is third in line to the British throne behind his father and grandfather Prince Charles, was born on Monday afternoon at London's St Mary's Hospital, and the new father has now issued a short statement following his son's birth, insisting, "We could not be happier." William, 31, is expected to spend his first night as a father with his wife and child at the Paddington hospital, where he and his brother Harry were born. The Queen and Prince Charles have also acknowledged the birth, with first-time grandfather Charles stating, "Grandparenthood is a unique moment in anyone's life, as countless kind people have told me in recent months, so I am enormously proud and happy to be a grandfather for the first time." Meanwhile, royal doctor Marcus Setchell appears to be just as excited about the royal baby as the family, telling members of the media the newborn is a "wonderful" and "beautiful" child. And British Prime Minister David Cameron has also issued a statement to the media about the birth. He writes, "I'm delighted for the Duke and Duchess now their son has been born. The whole country will celebrate. They'll make wonderful parents." Speaking outside his residence in Downing Street, London, he added, "It is an important moment in the life of our nation, but I suppose above all it's a wonderful moment for a warm and loving couple." U.S. President Barack Obama has also sent his best wishes to the new parents, stating, "(Wife) Michelle and I are so pleased to congratulate The Duke and Duchess of Cambridge on the joyous occasion of the birth of their first child. We wish them all the happiness and blessings parenthood brings. Given the special relationship between us, the American people are pleased to join with the people of the United Kingdom as they celebrate the birth of the young prince." And Ellie Goulding, who performed at the royal couple's wedding reception in 2011, took to Twitter to gush, "Congratulations to two of the loveliest people in the whole world on their baby boy. I am so happy for them." Bette Midler, Queen Latifah and The Saturdays star Mollie King also offered up their thoughts on Twitter, as did funnyman Steve Martin, who joked, "I would be so honored if they named the royal baby, 'Steve Martin.'"