HONG KONG — President Rodrigo Duterte of the Philippines, a populist with a reputation for making crude jokes about women, came under fire on Monday by critics who accused him of abusing his authority after he publicly kissed a woman on the lips at an event in Seoul, South Korea.

Addressing a group of overseas Filipino workers on Sunday in Seoul, Mr. Duterte called two women on stage with him, and asked one for a kiss in exchange for a book he planned to present them.

“Are you single?” Mr. Duterte asked the woman — identified by the state-run Philippine News Agency as Bea Kim — as seen in a video that has since been shared widely online. “You’re not separated from him?” he asked in reference to Ms. Kim’s husband, adding, “But can you tell him that this is just a joke?”

Ms. Kim appeared to be a flattered, excited fan of the president and to consent before Mr. Duterte kissed her on the lips to cheers from a crowd of about 3,000 people.