A week before he celebrated his 99th birthday, former US President Jimmy Carter was spotted at the Peanut Festival held in his hometown of Plains, Georgia.

The 39th US president (1977-1981) was riding in a car with his wife Rosalyn, 96.

“Beautiful day for the President and Mrs. Carter who enjoyed a ride on the grounds of the Plains Peanut Festival! Just a week before he turns 99. We bet peanut butter ice cream will be on the menu for lunch,” the Carter Center said in a post on Platform X (formerly Twitter), which shared video of the couple’s rare public appearance.

“It was a big surprise! And yes, we sang ‘Happy Birthday’ to him,” Erika Bettis Williams, who captured the Carters’ surprise appearance, told CNN.

Jimmy Carter is the oldest living former US president. In recent years he has been facing serious health problems. In 2015, he revealed that he had been treated for melanoma, which had metastasized to his liver and brain.

The Carter Center had announced in February that the former US president would receive medical care at home so that he could spend the rest of his life near his family.