"They were supposed to get married in June, but there have been so many problems with them, they thought it was best to work out their issues before making such a big commitment," femalefirst.co.uk quoted a source as saying.
"They aren't ready. Their families are both concerned. They don't want to see Cyrus and Hemsworth get married and then get divorced. They're very young to be getting married," the source added.
However, Hemsworth's elder brother Luke recently described Cyrus as a big part of their family.
However, Hemworth's sister-in-law Elsa Pataky hinted earlier this week that she isn't sure if the wedding was still on the horizon.
She said: "I don't know. If they get married it would be nice to go."