American reality television star Kylie Jenner has finally admitted that her lips are fake.

In a clip from the upcoming episode of Keeping Up With The Kardashians, the 17-year-old revealed that she has gotten lip filler.

"I have temporary lip fillers, it's just an insecurity of mine and it's what I wanted to do. I'm just not ready to talk to reporters about my lips yet because everyone always picks us apart. I want to admit to the lips, but people are so quick to judge me on everything, so I might have tiptoed around the truth, but I didn't lie," she said.

Rumours that Kylie has gone under the knife started after her lips in the selfies on her Instagram account looked plump and full.

Brown lips ... ?

A photo posted by Kylizzle (@kyliejenner) on

makeup by yours truly

A photo posted by Kylizzle (@kyliejenner) on

However, she took to social media to deny lip augmentation reports.

Last month, many teens took up the Kylie Jenner Lip Challenge, an online trend where participants placed a glass or plastic cup around their lips and sucked on it for five minutes, resulting in a swollen, but bruised pucker.

Kylie responded to the challenge on Twitter and encouraged her fans to be themselves.

"I'm not here to try & encourage people/young girls to look like me or to think this is the way they should look," she wrote.

"I want to encourage people/young girls like me to be YOURSELF & not be afraid to experiment w your look."