"The measures we have taken... must be extended beyond their original deadline," Conte told the Corriere della Sera newspaper early on Thursday morning following a meeting with ministers at Palazzo Chigi.
Conte referred to the closures of many businesses, "individual activities" and the shutdown of schools.
He did not give a date or any further details on the extension of the measures.
Imposed nationally on March 12, the shutdown of most businesses and a ban on public gatherings in Italy, the European country worst hit by the pandemic, are due to expire on March 25.
School closures and other measures, such as a ban on fan attendance at sporting events, are due to run on until April 3.
"We have avoided the collapse of the system. The restrictive measures work," Conte said.
Italy reported a record high 475 deaths in one day on Wednesday, bringing the total number of fatalities near 3,000.
The total number of confirmed cases in Italy, including the deceased and recovered, has passed 35,000.
Conte expressed hope that the country will hit a peak in a few days and see a decline in infection rates.
But he warned "we will not be able to return immediately to life as it was before" even after worst is over.