Korean actress Jeon Do-yeon has won the best actress award at the Cannes Film Festival for her role as a grieving mother and wife in "Secret Sunshine."

Jeon played a piano instructor in the film who struggles to forgive the killer of her son.

The 34-year-old actress said she will never forget everyone at Cannes who welcomed the film and thanked former South Korean culture minister and director of the film, Lee Chang-dong, and her costar in the film, actor Song Kang-ho.

It is the first time for a South Korean actress to win an international film award since Kang Soo-yeon won best actress at the Venice Film Festival 20 years ago.

"Secret Sunshine," a melodrama about death and faith, was one of the 22 films competing for the prize at the French film festival.

Romanian director Cristian Mungiu won the Cannes Film Festival's top prize, the Golden Palm, with "Four Months, Three Weeks and Two Days," a harrowing portrait of an illegal abortion in Communist-era Romania.