The firm said it wanted to conduct extra tests following screen problems reported by early reviewers of Samsung's Galaxy Fold.
Both firms had unveiled the devices in February but Huawei said it now wanted to be "cautious".
Samsung currently has no release date for the Fold.
Huawei confirmed to the BBC that the Mate X is expected to launch in September 2019.
"We don't want to launch a product to destroy our reputation," it told CNBC.
"The Mate X was always going to come later than Samsung's Galaxy Fold, but the Korean phone maker's problems have certainly given Huawei more breathing space," said Ben Wood from CCS Insight.
"There is little doubt Huawei will have learned lessons from Samsung's problems and - given the extra scrutiny the Mate X will get as a result - Huawei is well advised to ensure it has every eventuality covered."
Huawei has also scrapped a new laptop launch this week because of its current position on a US trade blacklist.
It is accused of having committed bank fraud to evade Iran sanctions, and obstruction of justice, among other violations.
The firm denies any wrongdoing.