On the first day of his week-long American tour, Prince Harry made a most charming appearance at a Mother’s Day tea hosted by first lady Michelle Obama.

Looking dapper in a dark suit and tie, Harry surprised the guests of the White House event on Thursday afternoon. He mingled with children backstage as they assembled gift bags for their mothers, then emerged in a formal dining area before the moms themselves, who cheered and gasped at his presence

Harry’s final stop during his current tour will be in Greenwich, Conn., to play in a polo match. The proceeds will benefit the prince’s Sentebale charity that helps African children in need.

“You all never complain, never complain, you just keep moving it along, getting it done, and I hope that you know how much this country appreciates you,” she said.

She also called her mother, Marian Robinson, “my rock” and thanked her for teaching her patience.

Children accompanying their moms slipped into the State Dining Room to gather tulip and rose bouquets, baked vegetable chips and edible dough jewelry to present to their mothers.

The families dined in the East Room on light fare, including smoked salmon sandwiches, vegetable spring wraps, corn madeleines, mini cupcakes, bonbons and chamomile tea.