Image copyright Olivier Douliery/Getty Images Image caption Vice President Biden wrote that he was "filled with furious anger"

Vice President Joe Biden penned an open letter on Thursday to the Stanford University sexual assault victim whose message to her assailant went viral.

Mr Biden sent the letter to BuzzFeed, praising the young woman for sharing her account with the public.

The unnamed victim's impact statement was read by millions after it was published by BuzzFeed last week.

In a response to her message, Mr Biden wrote that he was "filled with furious anger" over what happened to her.

"You were failed by a culture on our college campuses where one in five women is sexually assaulted - year after year after year," Biden wrote in the letter, entitled, An Open Letter to a Courageous Young Woman.

"The millions who have been touched by your story will never forget you".

The victim, now 23, read her statement aloud to her assailant, 20-year-old former Stanford University student Brock Turner, after he was convicted of sexually assaulting her while she was unconscious.

Mr Turner, a former swimmer at Stanford, was found guilty in March of three felony charges.

Prosecutors said that in January 2015, two witnesses tackled Mr Turner to the ground after seeing him sexually assault a woman, who was lying unconscious.

Image copyright AP Image caption Brock Turner was seen by two witnesses sexually assaulting an unconscious woman

But a judge expressed concern about the impact prison would have on Mr Turner, sentencing him to six months in county jail. He had faced up to 14 years in prison.

Mr Turner is also required to register as a convicted sex offender for the rest of his life.

Mr Turner's father issued a statement to the court before the sentencing, saying his son was paying a steep price for only "20 minutes of action" and did not deserve a long sentence as he had no prior criminal history.

Image copyright Twitter - @mldauber

Mr Turner's sentence and his father's letter sparked public outrage on social media, prompting calls for the judge to resign.

Nearly a million people have also signed a petition to recall the sentencing judge, Aaron Persky, for what they described as a "lenient sentence."

The cast of the TV show Girls have also made a video backing the woman and other victims of sexual assault.

Mr Biden, who is involved in the White House campaign against campus sexual assault, is the latest public figure to speak out on the case.

"It must have been wrenching - to relive what he did to you all over again. But you did it anyway, in the hope that your strength might prevent this crime from happening to someone else", Mr Biden added. "Your bravery is breathtaking."