US pop icon Taylor Swift has donated more than £23,000 (26,000 euros, $31,000) to a London schoolgirl raising funds to go to university.

Vitoria Mario, 18, won a place to study mathematics at Britain's University of Warwick but could not afford to support herself.

She asked hundreds of companies for help and even posted notes through the letter boxes of homes in affluent areas, but in desperation turned to online crowdfunding -- and Swift got in touch.

"Vitoria, I came across your story online and am so inspired by your drive and dedication to turning your dreams into reality," the pop star wrote after donating £23,373. 

"I want to gift you the rest of your goal amount. Good luck with everything you do! Love, Taylor."

Swift made no public statement about the donation but her official Twitter account liked a tweet about the story posted by one of Mario's friends.

Mario said the donation "blew my mind", telling BBC television: "I call it a blessing."

According to her GoFundMe page, Mario moved to London four years ago from Portugal speaking no English, but got top marks in all her exams.

She set herself a target of raising £40,000 for university accommodation and living costs over four years -- which she has now exceeded.

"Sadly, my father has passed away, and my mother remains in Portugal. Moving away from her was a challenge but it was a sacrifice worth being made, in my family's eyes," she wrote.

According to US media, Swift has previously made impromptu donations to fans and since the coronavirus outbreak began, has sent a box of merchandise to a nurse in Utah and helped support workers at a shuttered Nashville record store.