In a release from the country's U.S. Embassy and Consulates, Italy said Wednesday that beginning on Tuesday travelers from the U.S. may only enter if they present a negative molecular PCR or rapid antigen test result carried out within 72 hours of arrival and either an anti-COVID-19 vaccination certificate for a European Medicines Agency (EMA)-recognized vaccine or a medical certificate confirming recovery from the virus dated no more than six months before departure.
Those who are unable to present a valid vaccination or recovery certificate will be required to self-isolate on arrival for five days and take a molecular PCR or rapid antigen test at the end of that period.
In addition, travelers are required to complete an online digital passenger locator form.
Travelers who want to visit certain locations are also required to show a "Digital Green Certificate/Green Pass" or an anti-COVID-19 vaccination certificate.
This comes as the European Union (EU) recommended Monday that its 27 nations reimpose restrictions on U.S. tourists – removing America from its "safe list," which is updated every two weeks.
However, member countries will keep the option of allowing fully vaccinated U.S. travelers in and the EU has no unified COVID-19 tourism policy.
The U.S. has yet to reopen its borders to EU tourists.
Heightened regulations in Italy come after Germany added the U.S. to its "high-risk" list and the U.S. extended the closure of its land borders to nonessential travel with Canada and Mexico through Sept. 21.
"In coordination with public health and medical experts, DHS continues working closely with its partners across the United States and internationally to determine how to safely and sustainably resume normal travel," The Department of Homeland Security said in an August 20 tweet.
U.S. cases have spiked in several states, and hospitals across the country are at capacity and running out of staff members.
The nation is averaging more than 155,000 new cases and 1,200 deaths per day.
Just over 61% of the eligible population of the U.S. is vaccinated, whereas EU countries have inoculated close to 70% of those over the age of 18.
The Associated Press contributed to this report.