So-called clandestine migrants from the European Union and Turkey would have to be returned to either side under the terms of a "readmission" agreement endorsed by the European Parliament.
Renate Sommer, a German member of Parliament, said agreement will benefit security for both sides.
"[It will] make a significant contribution to curbing irregular immigration into the EU via Turkey, help combat cross-border crime, particularly human trafficking," she said in a statement Wednesday.
Turkey aspires to a closer relationship with the EU. The latest phase of accession talks -- Chapter 22, dealing with regional policy -- began Nov 5.
Turkish Foreign Minister Ahmet Davutoglu met earlier this month in Brussels to discuss EU cooperation with Neighborhood Policy Commissioner Stefan Fule and Catherine Ashton, the top EU foreign policy official.
EU leaders said there was a "strong desire" from both sides to advance talks further.
"The readmission agreement will benefit Turkey as well as the EU," Sommer said. "Now it is up to Turkey to fulfill its obligations to implement the agreement in full."