Hollywood superstar and conservationist Harrison Ford on Thursday called on the United States to ratify the Convention on Biological Diversity, saying increasing biodiversity loss makes it imperative that Americans understand the importance of the treaty.

"If American voters are aware of the critical nature of biodiversity, they will impress upon their leadership that (ratification) is an important political requirement," Ford said in an interview with The Japan Times. Ford is visiting COP10 in his capacity as vice chairman of Conservation International, a Washington-based nonprofit.

Ford pointed to public education on environmental issues as the key to mustering political will on ratification. Too many people, he said, were confused about the meaning of biodiversity because environmentalists had spent too much time promoting one endangered species or another rather than looking at the system as a whole.