Reality TV star Kim Kardashian West is "so sad" to be working on Mother's Day, which falls on second Sunday in May.

The "Keeping Up with the Kardashians" star, who has 22-month-old daughter North with husband Kanye West, is scheduled to fly to South America to promote her new book, "Selfish", ahead of the US holiday on Sunday, reports femalefirst.co.uk.

Asked about her plans, Kim said on "Extra" TV show: "I'm actually so sad that I'm going be in Brazil for Mother's Day, so we're doing something the day before. Mother's Day is kind of pretty low-key.

"I saw my daughter doing a whole arts and crafts thing, her and (my niece) Penelope were. So, I'm sure that she made me something really special."

Kim's daughter has also made something for her mother, Kris Jenner, and older sister Kourtney, 36, for the occasion.

She said: "North prepared this thing for my mom and Kourtney so she'll take over for the day."