"This is not only a question of political wishful thinking, but also a good economics," EIB President Werner Hoyer told a green finance summit organised by the French government on Thursday.

The EIB last year rewrote its energy lending rules to stop funding unabated fossil fuel power plants from the end of 2021, with certain exemptions.

Hoyer said continuing to finance fossil fuel infrastructure could see banks end up with stranded assets.

"It's a question of economic rationality, not to embrace something that you know you'll have to write off in 15 or 20 years, but you have on the balance sheet for 40 years," Hoyer said, adding that he hoped public and private institutions can "close ranks" around the issue.

(Reporting by Kate Abnett; editing by Simon Jessop)