It was during Justo's term that Argentina signed the Roca-Runciman Treaty with the United Kingdom, which assured the UK a provision of fresh meat in exchange for important investments in the field of transportation in Argentina, given certain economic concessions from Argentina, such as giving control over the public transport in Buenos Aires to a British company, the Corporación de Transportes.
Tijekom Justovog mandata Argentina je potpisala sporazum Roca-Runciman s Velikom Britanijom, koji je osigurao Velikoj Britaniji isporuku svježeg mesa u zamjenu za važna ulaganja na području prijevoza u Argentini i dao im određene gospodarske ustupke u Argentini, poput davanja kontrole nad javnim gradskim prijevozom u Buenos Airesu britanskoj tvrtki "Corporacion de Transportes".