London: Singer Demi Lovato says she wouldn't be able to survive without her best friend Miley Cyrus.

The 19-year-old says she shares a love-hate relationship with Cyrus, 19, but at the end of the day they reunite.

'No matter how many times we fight, we will always be in each others' lives, but (Miley and I) are very strong-headed, so when we fight, it's brutal and we're like, 'We're never going to be friends again,' Then, two days later, we're like, 'I love you and I miss you',' a website quoted Lovato as saying.