Italy will tighten restrictions for arrivals from the rest of the EU from Thursday, requiring coronavirus tests of everyone and a five-day quarantine for those who are not vaccinated.
Previously, EU arrivals had to show proof of vaccination, recent recovery or a negative test.
The decree signed by Health Minister Roberto Speranza late on Tuesday "provides for the obligation of a negative test on departure for all arrivals from European Union countries", a spokesperson said.
"For the unvaccinated, in addition to the negative test, a five-day quarantine is planned."
Unvaccinated people arriving from outside the bloc must already quarantine, and tests are required of those with jabs.
The new measures, valid from December 16 to January 31, come as Europe battles a fresh wave of coronavirus infections sparked by the spread of the new Omicron variant.
Early data suggests it can be resistant to vaccines and is more transmissible than the Delta variant, which currently accounts for the bulk of the world's coronavirus cases.
Italy was the first EU country to experience a major outbreak of Covid-19 in early 2020.
In recent months, it has sought to control infections through the use of health pass showing proof of vaccination, recent recovery or a negative test for everything from going to work to eating in restaurants.
More than 20,000 new cases were reported in Italy on Tuesday, and another 120 deaths.