"IMF analysis suggests that, if everyone lived three years longer than expected, pension related costs could increase by 50 per cent in advanced and emerging economies.
"This would heavily affect private and public sector balance sheets and could also undermine financial stability."
Ms Lagarde said governments needed to pursue "game changing" policies to ensure pension systems become sustainable.
IMF chief, Christine Lagarde, in 2016:
"IMF analysis suggests that, if everyone lived three years longer than expected, pension related costs could increase by 50 per cent in advanced and emerging economies.
"This would heavily affect private and public sector balance sheets and could also undermine financial stability."
Ms Lagarde said governments needed to pursue "game changing" policies to ensure pension systems become sustainable.