Did Italy face off against Romania!?!?
An illegal camp housing Romanians has been dismantled near Rome
EU officials say Italy is acting within its rights provided it respects the union's criteria for expulsion of EU citizens and does not target a group.
Under European law, EU countries can expel EU citizens who pose a public threat or who lack sufficient income.
Italy is deporting some Romanians under a new decree aimed at tackling crime.
"It is possible to expel citizens of another [EU] state if they don't fulfil the [residency] criteria or represent a threat to public safety or public health," EU justice affairs spokesman Friso Roscam Abbing said on Monday.
But he added that "there cannot be a situation of group expulsion or group assessment".
Italy's emergency move prompted Romanian officials to ask whether it violated European law, which allows EU citizens to travel freely across member states' borders.
The Italian decree, adopted last week, allows for the swift deportation of immigrants deemed to be a threat to public safety. It has not yet been approved by the national parliament.
"The Romanian state... will not accept the humiliation of hundreds of thousands, or millions, of people"
- Traian Basescu Romanian president
Romanian Prime Minister Calin Popescu Tariceanu will go to Rome to discuss the situation with his Italian counterpart Romano Prodi.
Romanian President Traian Basescu has urged the European Commission to study the Italian decree to see whether it complies with EU law.
Romania is also sending 30 policemen to Italy to help deal with the Romanian cases.
Mr Prodi defended the decree, saying it was "necessary but also just", in an open letter to Italy's Il Messaggero daily.
But he also warned against "criminalising a nation because of the fault of one individual or a minority".
More than half a million Romanians live in Italy - and about 20 have been sent home so far in the new crackdown.
Bucharest has warned against a wave of xenophobia, following an assault on three Romanians by a mob of Italians in Rome on Friday.
The situation, already tense, reached a critical point in late October, when Nicolae Romulus Mailat, a Romanian citizen, was charged with the murder in Rome of Giovanna Reggiani.
Romanian authorities describe Mailat as an ethnic Roma (Gypsy). He had been living in an illegal shanty town at Tor di Quinto on the edge of Rome, inhabited mainly by Roma. Italy demolished the shacks there at the weekend.
More than 1,000 foreigners risk being expelled under the decree, Italian media report.