The total number of relocations now stands at 16,340, the executive said on Wednesday.
However, it also admitted that more effort was needed from all member states to ensure that people eligible are relocated over the coming months.
On resettlement, EU members had continued to make significant progress with safe and legal pathways being provided, European Commissioner for Migration, Home Affairs and Citizenship Dimitris Avramopoulos said.
Speaking in Brussels, he said the Commission had now issued targeted recommendations to help improve the relocation and the resettlement process.
Avramopoulos said, "In March, we reached a new record number of people relocated. This is solidarity in action and a demonstration of responsibility. Now is the time for our member states to deliver on their commitments and to intensify their efforts. They have a political, moral and legal duty to do so. I call on those countries that have not yet joined this common effort to do so."
He went on, "Relocating all people eligible from Greece and Italy over the coming months is perfectly feasible. At the same time, we managed to resettle over two thirds of the 22,500 people we committed to offer a safe and legal path to in July 2015."
The official said, "This is welcome news. We are delivering on our commitments to share responsibility with third countries such as Turkey, Jordan and Lebanon."
Meanwhile, the Commission also announced on Wednesday that it plans to introduce new measures to "reinforce the protection of all migrant children at all stages of the process."
Over the past two years, a growing number of children in migration have arrived in the EU, many of them without their families.
While EU and member states' legislation provide a framework for protection, the Commission admits that the recent surge in arrivals has put national systems under pressure and exposed gaps and shortcomings.
The Commission is proposing a number of priority areas to focus on to improve the protection of children in migration and ensure a closer link between the asylum and child protection services
These include swift identification and protection upon arrival; adequate reception conditions for children and swift status determination and effective guardianship.
Avramopoulos added, "One in three asylum seekers in Europe is a child. Children are the most vulnerable migrants and ensuring their protection from the moment they leave their home countries should be mainstreamed in our migration policy.
"This means that we need a comprehensive and stepped-up response. Both the Commission and our EU agencies stand ready to move forward to implement these actions."
Commission First Vice-President Frans Timmermans added, "We need to make sure that children who need protection actually receive it. And we need to do it now. This is our moral duty as well as our legal responsibility."