Louis Tomlinson thinks Justin Bieber should have finished his 'Purpose World Tour'.

The 23-year-old singer recently announced he was cancelling the final 14 dates on his extensive 18-month tour due to ''unforeseen circumstances'' which have seen been reportedly linked to ''exhaustion'', but One Direction hunk Louis believes the star should have ''seen it through'' to the end out of love for his fans.

Speaking to 92.3 AMP Radio, the 25-year-old 'Back To You' hitmaker said: ''Obviously, you have to be in a good position mentally, but I also think, to a certain degree, when you're signing up to something, you should see it through.

''There's never enough that I can say or do for the fans, and honestly, I think people can forget that to be quite honest. The whole game is so exciting and crazy, but at the end of the day, it's the people who are buying the records that are putting you where you are.''

Meanwhile, it was recently claimed that the 'Sorry' hitmaker is ''truly exhausted'' after battling a tough touring schedule.

A source said: ''He didn't feel like he could give the rest of the tour as much energy as his fans deserve. He is a perfectionist and didn't want to disappoint fans with some half-ass performance. He thinks his fans deserve and should expect the same performance at the end of the tour as in the beginning. He just didn't have that passion right now. He is truly exhausted.''

And whilst the insider insists this cancellation doesn't mark a permanent end to the 'Sorry' hitmaker's touring days, the star does need time to ''focus on [his] own mental health.''

They added: ''It's a mental exhaustion that very few people understand. It seems very fair, although understandably disappointing to his fans, that he canceled the rest of the tour. It's a mature way of saying, 'Sorry, I need to focus on my own health for a bit.'

''It wasn't an easy decision for him. He has had this feeling before though and knows he has to just take a break from performing. It doesn't mean he will never tour again - of course he will. He loves touring. Let the guy rest, and he will come back even better.''