Greece’s Hellenic Republic Asset Development Fund has identified 40 uninhabited islands and islets that could be leased for as long as 50 years to reduce debt as pressure grows on the country to revive an asset-sales plan key to receiving international aid.

“We identified locations that have good terrain, are close to the mainland and have a well-developed infrastructure and, at the same time, pose no threat to national security,” Andreas Taprantzis, the fund’s executive director for real estate, has said. “Current legislation doesn’t allow us to sell them outright and we don’t want to.”

The fund is charged with raising 50 billion euros ($64 billion) from state assets by 2020 to meet conditions tied to pledges of 240 billion euros in foreign aid. As international inspectors in Athens scrutinize the country’s fitness to receive the latest aid payment, Prime Minister Antonis Samaras has said commercial exploitation of some islands could generate the revenue lenders need to see to continue funding the country.

The shortlist includes islands ranging in size from 500,000 square meters (5.4 million square feet) to 3 million square meters, and which can be developed into high-end integrated tourist resorts under leases lasting 30 years to 50 years, Taprantzis said.