"A very close-held operation": How Biden made his unannounced visit to Ukraine

Sneaking the leader of the free world into an active war zone in Ukraine isn't easy. 

It took months of secret planning by a handful of officials from the Pentagon, Secret Service, intelligence community and White House. Amanda Sloat, a top adviser to President Biden on European affairs, told CBS News "an incredibly small team" was involved in the planning. 

"It was a very close-held operation, and I think everybody wanting to do everything they could to get the president there and back safely," Sloat said.