"I've had a bit of a bicycle accident," wrote the star on his Instagram page, posting a picture of his arm in a cast.
"I'm currently waiting on some medical advice, which may affect some of my upcoming shows. Please stay tuned for further news."
The 26-year-old was on a break from his world tour, but was due to resume with a gig in Taipei next week.
He has a further 14 dates scheduled this year, including concerts in Japan, South Korea and Thailand, before kicking off the Australian leg of his tour in March 2018.