A ruling by the EU's top court has dealt a further blow to Italy's attempts to create a fast-track system in Albania for processing asylum applications offshore.

Europe's top court on Friday questioned the legitimacy of the "safe countries" list Italy uses to send migrants to Albania and fast-track their asylum claims, in a fresh blow to a key plank of the government's migration policy.

While ruling Italy's plan to fast-track migrant deportations is legal, the European Court of Justice set out some limits. Those include disclosing sources for their assessment of a country being considered "safe.