"The emergency expulsion decree for EU citizens who pose a public and social danger was a necessary action but also a fair one," he wrote in an open letter published in the Il Messaggero newspaper.
On Tuesday, parliament will debate whether the deportation policy should become permanent.
Prodi has warned against "criminalising" the whole community.Guarantees
However, Giovanni Russo Spena, a member of the Italian parliament, told Al Jazeera that the policy risked doing exactly that.
"It is one thing to deport foreigners to commit crimes, it is another to deport a whole people. It seems like the measures that were taken against the Jews in the 1930s," he said.
|"We don't want those who are working honestly to become victims of Italian police action" |
Calin Tariceanu, Romanian prime minister
"We want guarantees that only those that are a security threat will be expelled from the country."
Hundreds more Romanians face expulsion under the emergency decree, while many others have left fearing reprisals.
Masked Italians beat up three Romanians on Friday in an incident widely believed to be linked to the fatal assault on Giovanna Reggiani, the wife of a high-ranking naval officer, three days earlier.
Tariceanu has announced steps for "resolving the crisis situation" including legal aid and additional consulates in Italy.
"We don't want those who are working honestly to become victims of Italian police action," he said.
Romanians make up Italy's largest immigrant community, numbering some 342,000 according to the ISTAT statistical institute and more than 500,000 according to the Catholic organisation Caritas.