Michelle Obama congratulates duke and duchess of Cambridge on royal baby

Former first lady Michelle ObamaMichelle LeVaughn Robinson ObamaMichael Avenatti, please go away Minnesota GOP Senate candidate compared Michelle Obama to a chimp in Facebook post Former Clinton aide Reines: ‘Party of snowflakes’ suddenly remodeled as 'angry mob of terrorists’ MORE on Monday posted a message of congratulations to the the United Kingdom's duke and duchess of Cambridge, Prince William and Kate Middleton, on the birth of their new baby.

On her Instagram page, Obama posted a photo from a past visit with the royal family, featuring former President Obama, William and Prince George, the oldest child of William and Kate. The photo, in which George is wearing a bathrobe, went viral after the 2016 visit.

“Barack and I are thrilled to congratulate The Duke and Duchess of Cambridge on their newest arrival!” she wrote. “We hope to meet him soon for a Kensington Palace pajama party. I’ll wear my robe!”

Kate gave birth Monday to a boy, who is now fifth in line to the British throne.

The Obamas are close with the William and his brother, Prince Harry, but will not attend Harry's wedding to American actress Meghan Markle next month, as the couple has decided not to have any official political leaders as guests.