Former first lady Michelle Obama was speaking at the Pennsylvania Conference for Women with TV producer Shonda Rhimes on Tuesday when her husband, former President Barack Obama, surprised her by dropping in via video to share a 25th-anniversary message with her and the audience.

"You have also been an example to our daughters and to the entire country. Your strength, your grace, your determination, your honesty, the fact that you look so good doing all of this," Barack said in the video which was later posted to his Facebook page.

"It's no wonder that as people got to know you the way that I got to know that they fell in love," the former president added.

Michelle also shared an anniversary message to her husband earlier on Tuesday.

"Happy 25th anniversary @barackobama. A quarter of a century later, you're still my best friend & the most extraordinary man I know. I love you," she tweeted.