"If people in other provinces do not honour (health guidelines), they may experience the fourth wave as well," Xinhua news agency quoted Rouhani as saying on Saturday.
"According to the statistics, compliance with health guidelines has decreased," he warned.
On Saturday, the Health Ministry registered 11,420 new Covid-19 cases, raising the overall caseload to 1,920,394.
The pandemic has so far claimed 62,999 lives in Iran, up by 123 in the past 24 hours, said Sima Sadat Lari, spokeswoman for the Ministry.
Of the newly infected, 1,060 were hospitalised, she added.
A total of 1,642,418 people have recovered from the disease and been discharged from hospitals, while 4,024 remain in intensive care units, she noted.
According to the spokeswoman, 13,038,709 tests for the virus have been carried out in Iran by Saturday.
Currently, 47 Iranian cities are on red alert for a high risk of infection, while 126 others on orange alert for a medium risk, the spokeswoman said.
Iran reported the first coronavirus cases in February 2020.
Visit news.dtnext.in to explore our interactive epaper!
Download the DT Next app for more exciting features!
Click here for iOS
Click here for Android