MANILA • Philippine President Rodrigo Duterte has defended his kissing a married Filipino woman on the lips, but said he will resign if enough women are offended and sign a petition calling for him to step down.

Mr Duterte has described Sunday's kiss in South Korea as "pure showbiz" intended to entertain a crowd of Filipino expatriates.

Feminists called it his "perverted way" of taunting female critics who are angered by his frequent derogatory comments, some of a sexual nature.

"If there are enough women to... Well I think if all women here would sign a petition for me to resign, I will resign," Mr Duterte told a media briefing around midnight on Tuesday upon his return from an official visit to South Korea.

Social media was abuzz with photos and videos of Mr Duterte on stage asking an unidentified woman from an audience of Filipinos to kiss him in exchange for a book he was handing out. The woman, who appeared excited to see Mr Duterte in person, agreed.

Mr Duterte, who enjoys rock star status among many Filipinos overseas, said kissing women was his "style" during his 22 years as mayor in Davao City prior to becoming President of the Philippines.

"During the campaign in my mayorship days, I kissed every woman there, lips to lips," the 73-year-old Mr Duterte said. "The problem is you don't know me."

Mr Duterte's controversial remarks about women include several public jokes about rape. But none has dented his domestic support and many Filipinos view his politically incorrect, earthy language as part of his appeal.

Women's rights advocates in the Philippines recently launched an online #BabaeAko (I Am A Woman) campaign to send a message that they were not taking Mr Duterte's "sexist" statements sitting down.

Presidential legal counsel Salvador Panelo yesterday said the kiss showed Mr Duterte's caring, fatherly character, and that the recipient in Seoul enjoyed the moment.

"She did it willingly and excitedly, she was tickled pink," he told news channel ANC.

REUTERS