Tunisia on Friday agreed to take back 1,500 Tunisian migrants from Germany who were denied asylum.
During her visit to the country, German Chancellor Angela Merkel said she wanted to speed up the deportation process after the Berlin Christmas market attack by a Tunisian; 12 people were killed in the attack.
Anis Amri, 24, had been denied asylum six months before carrying out the attack.
Merkel has come under heavy pressure for policies that allowed a million refugees into Germany in two years.
"We have agreed with Tunisia to send back 1,500 Tunisians from Germany who have been refused permission to stay in Germany," Merkel said at a news conference with Tunisian President Beji Caid Essebsi in Tunis.
"Those who want to return voluntarily will be able to receive aid."
Essebsi said Tunisia would send a delegation to verify the identities of those returning.
Merkel also said the her government would provide Tunisia with €250 million in aid for development projects.
Meanwhile, German authorities have detained another Tunisian man they suspect of being involved in the truck attack.