The FAST project aims to combat the introduction, naturalization and spread of invasive alien species that harm biodiversity, a phenomenon that is particularly important in cross-borderareas, for the greater ease of interchange, and which requires timely and urgent action. The activities will be carried out within sites with terrestrial and aquatic environments with a high cross-border character. Four Sicilian sites of the Natura 2000Network have been identified (Riserva naturale Foce del Fiume Simeto and Lago Gornalunga, Riserva naturale Fiume Fiumefreddo, Riserva naturale Foce del Fiume Irminio e Riserva naturale Vallata del Fiume Ippari) and three Maltese sites (L-Inħawi tal-Buskett u tal-Girgenti, L-Inħawi tax-Xlendi u tal-Wied tal-Kantra, Il-Magħluq tal-Baħar ta' Marsaskala). FAST will proceed with the recognition of invasive alien species and their classification into priority scales, their containment and/or eradication and the identification and management of pathways (especially two-way cross-border) and introduction and diffusion vehicles. Guidelines will then be drawn up and best practices adopted. The creation of a dedicated website and communication plans on environment will ensure the maximum dissemination of the results achieved. The FAST project will help to halt the loss of biodiversity of indigenous species in protected areas on the two islands, through the monitoring and conservation of invasive alien species, and the implementation of effective restoration actions.