Lana Del Rey reportedly couldn't say no to performing at Kanye West and Kim Kardashian's upcoming wedding.

The 36-year-old rapper is marrying Kardashian this weekend in Europe and it's claimed he shelled out huge amounts of cash to get the singer to perform at the ceremony.

It's claimed when West proposed to Kardashian last year Del Rey declined to take part in the event but this time around she is completely swayed.

"Kanye knew how much Kim loved Lana's music, which is why he tried to get her to perform at the proposal," a source told UK newspaper The Mirror.

"So he upped the offer to perform at the wedding and told Lana that it's his and Kim's special song and it would mean so much to have her perform it. She couldn't say no."

West's over-the-top proposal at AT&T Park in San Francisco on Kardashian's birthday October 21 took place while an orchestral version of Del Rey's hit Young & Beautiful was played over the speakers.

Radar Online previously reported West wanted Dely Rey to sing the track there in person because it is one of Kardashian's favourite songs.

"Lana politely declined, and didn't give any reason for not being able to perform. It was a very firm no from Lana and her camp," a source told the outlet at the time.

"Kanye did try to push it, but didn't get anywhere. Kanye decided to hire an orchestra to perform the song for Kim, and he was much happier with how it turned out."

The song must be extremely special to Kim, as she tweeted about being besotted with it last summer.

"I can't get this Lana del Rey song out of my head! #youngandbeautiful," Kim wrote on Twitter.