Border control is in the interest not only of the Member States at whose external borders it is carried out but of all Member States that have abolished internal border control. Border control should help to reduce illegal migration, to combat the smuggling and trafficking of human beings, and to prevent any threat to the Member States’ internal security, public policy, public health and international relations. When carrying out border control, Member States are to act in compliance with relevant Union and international law, including the Geneva Convention Relating to the Status of Refugees of 28 July 1951, as amended by the New York Protocol of 31 January 1967, with obligations related to international protection, in particular the principle of non-refoulement, and with fundamental rights. As such, measures taken at the external borders are important elements of a comprehensive approach to migration, allowing Member States to address the challenge of mixed arrivals of irregular migrants and persons in need of international protection.