ROME — Italy and France agreed on Friday to carry out joint sea and air patrols to prevent Tunisian migrants from arriving in Italy, a move that appeared to ease tensions between them over how to contend with thousands of North African migrants who have landed in Italy since January.

After a meeting in Milan on Friday, Interior Minister Roberto Maroni and his French counterpart, Claude Guéant, said the two countries would work together to patrol the coasts and enforce an accord between Italy and Tunisia, a former French colony, on the return of migrants.

“We agreed on the need to develop a joint action between Italy and France on certain issues,” Mr. Maroni said. He added that both countries would “take initiatives to block the departure of illegal migrants from Tunisia.”