Invasive alien species are one of the main direct drivers of biodiversity loss. In some ecosystems, such as islands, invasive alien species are the leading cause of biodiversity decline. Invasive alien species affect biodiversity by competing with native species for resources, by direct predation or by introducing pathogens. They also modify the composition and structure of ecosystems, reducing the services they provide. In addition to their environmental impacts, invasive alien species pose a threat to food security, human health and economic activities. Globalization and an associated increase in human-mediated activities, such as international transport, trade and tourism, have made the movement of species beyond natural bio-geographical barriers easier and quicker, by creating new introduction pathways. Due to the wide and crosscutting impacts of IAS, including environmental, economic, health, social and cultural impacts, it is necessary to strengthen collaboration across sectors and government agencies at all levels and areas to ensure that this threat is managed effectively.