UPDATE 2-U.S., Canada must do more in climate fight -France

* U.S., Canada must make deeper CO2 cuts than planned

* Aviation should cut to 5 pct below 2005 levels by 2020

* Nations should mind U.N.'s "most cautious scenarios" (Updates with Canadian reaction)

By Pete Harrison and Julien Toyer

BRUSSELS, June 24 (Reuters) - The United States and Canada must do more than currently proposed to tackle greenhouse gases, France says in a position paper ahead of global climate talks in Copenhagen this December.

The government document seen by Reuters, titled: "Possible outline of a fair and ambitious agreement in Copenhagen," is the strongest message yet to the United States and Canada from within the European Union.

Paris also made the first concrete suggestions on how ministers in Copenhagen might tackle soaring emissions from aviation, but stopped short of suggesting emission curbs for shipping.

Airlines should cut emissions to 5 percent below 2005 levels by 2020, said the document, seen by Reuters on Wednesday.

It warned that Canada and the United States were not on course to cut emissions by the level needed, making it difficult for rich nations to meet the 25-40 percent collective reduction in greenhouse gases recommended by a U.N. climate panel.