Sima Sadat Lari said 177 people died during the 24 hours, pushing the official death toll to 24,478 in Iran, one of the hardest-hit countries in the West Asia.
The spokeswoman added 1,494 of the new positive cases have been admitted to the hospitals.
Among those undergoing treatment, 3,912 patients have critical conditions, Lari said.
At least 361,523 patients have recovered so far or have been discharged from hospitals across Iran, she continued.
The spike in the number of coronavirus cases came days after Deputy Health Minister Iraj Harirchi said the whole country is on red alert as daily deaths and cases increased at an alarming rate.
“The color classification doesn’t make sense anymore. We no longer have orange and yellow. The entire country is red,” Harirchi said on television on September 18.
“If the current course continues, the death toll will reach 45,000,” he warned.
Iran’s health officials have warned about a third wave of the outbreak, while the government has blamed the spike in infections partly on decline in public adherence to health protocols.
Iranian President Hassan Rouhani on Saturday called on people to observe the health protocols more seriously, warning against the outbreak of new epidemics as the cold season is approaching.
Tasnim News Agency and Reuters contributed to this story.