Niall Horan has reportedly split from his girlfriend because he's too busy for love.

The One Direction star ended his relationship with Amy Green - which began in October - because of his hectic schedule with the band which didn't leave him enough time to do ''everything he has to do.''

A source told the Sunday Mirror newspaper: ''Sadly, it is over between Niall and Amy. He finished it because he didn't have enough time with everything he has to do.

''Understandably she was disappointed because she had been in a relationship before she started seeing Niall and chose him over her boyfriend.

''But there are no real hard feelings and they're still close.''

However, an insider has claimed the 20-year-old aspiring actress-and-model threatened to break up with the 'Little Things' hitmaker earlier this month because Niall, 19, was too immature.

The source said: ''It was like [his] first relationship, whereas Amy had been in a relationship before. They had a few silly arguments and it was really the beginning of the end.''

While Niall is said to have never felt happier, his now ex-girlfriend has refused to comment on the split, although a close friend has said she hopes they'll stay friends.

Speaking outside her family's north London home, Amy said: ''I don't know what I should or shouldn't say. Sorry.''