The critical infrastructure of the defunct Chernobyl nuclear plant has not been damaged and essential maintenance work is ongoing, the European Bank for Reconstruction and Development (EBRD) said on Friday.

"The information we currently have is that the existing infrastructure of the New Safe Confinement and the Interim Spent Fuel Store 2 (ISF2) has not been damaged and the essential operational and maintenance tasks are being undertaken," the EBRD said in a statement to Reuters.

The former power plant was captured by Russian forces on Thursday after Russia launched a full-scale invasion of Ukraine, an adviser to the Ukrainian presidential office said.