By John Irish, Jarrett Renshaw and Andreas Rinke KANANASKIS, Alberta (Reuters) -Group of Seven leaders faced early challenges during meetings in Canada on Monday as U.S. President Donald Trump said removing Russia from the former Group of Eight over a decade ago had been a mistake.

Six of the Group of Seven leaders have discussed Russia’s war in Ukraine and international cooperation on key, non-military issues, wrapping up a summit that was forced to try and demonstrate how the wealthy nations’ club still can shape world events despite the early departure of U.