Ukraine on Tuesday unveiled the world's largest moveable metal structure over the Chernobyl nuclear power plant's doomed fourth reactor to ensure the safety of Europeans for generations to come.

"We welcome this milestone in the process of the transformation of Chernobyl as a symbol of what we can achieve jointly with strong, determined and long-term commitment" European Bank for Reconstruction and Development (EBRD) president Suma Chakrabarti said in a statement. The EBRD was the main sponsor of the 2.1 billion euros ($2.2 billion) project that took more than five years to complete.