(Port-au-Prince) -- The man in charge of the U.S. military's relief efforts in Haiti called Tuesday's earthquake in that country the most devastating and far-reaching disaster he's ever seen.

Lieutenant General Ken Keen told CBS' "Face the Nation" more than three-million people in the capital city of Port-au-Prince are affected, with many more facing hardships outside of the city.

He added helping Haiti recover will take the entire world's help, and said they're starting to see it happen.

Keen said while efforts are getting better every day, more needs to be done and done faster.