"We have seen a drop in the number of people leaving Libya for Europe this year, around 20 per cent," Enrico Credendino, commander of the force, told a news conference aboard the Cantabria ship at the port of La Goulette, near Tunis.
Summer saw a drop of 75 per cent compared with the same period in 2016, with the number dying at sea falling by 60 per cent, said the head of the EU's anti-trafficking operation dubbed Sophia.
"With the training we have done, they are now able to more effectively patrol territorial waters, fight all types of crime and also save lives," the commander said.
The EU ambassador to Tunis, Patrice Bergamini, called on Tunisia to help neighbouring Libya with its "know-how" on migration in support of Operation Sophia.
The European Union launched the anti-smuggling operation in 2015 after two shipwrecks killed 1,200 migrants in April that year.
The operation, which claims to have intercepted 117 smugglers and seized 482 of their ships, has been criticised for failing to effectively stop the smugglers.