More than 80 fact-checking organisations Wednesday urged online video platform YouTube to better combat disinformation, offering to help debunk false statements.

"Every day, we see that YouTube is one of the major conduits of online disinformation and misinformation worldwide," said the groups spanning the globe, from Politifact and the Washington Post in the United States to the Kenya-based Africa Check.

Videos containing false information had gone "under the radar of YouTube's policies, especially in non-English speaking countries", they said in an open letter to YouTube chief Susan Wojcicki.

"We urge you to take effective action against disinformation and misinformation... and to do so with the world's independent, non-partisan fact-checking organisations," they added.

"Our experience as fact-checkers together with academic evidence tells us that surfacing fact-checked information is more effective than deleting content."

It also urged the platform to make sure its recommendation algorithm did not actively promote disinformation to its users.

YouTube spokesperson Elena Hernandez defended the platform, saying that fact checking was a "crucial tool", but just "one piece of a much larger puzzle to address the spread of misinformation".

"Over the years, we've invested heavily in policies and products in all countries... to connect people to authoritative content, reduce the spread of borderline misinformation, and remove violative videos," she added.

She said YouTube had seen "important progress".