"I have been part of various disaster operations but I have never seen anything as devastating or far reaching," he told "Face the Nation" host Bob Schieffer Sunday. "This is affecting over three million people here in the Port-au-Prince area. I've flown over the area. I've walked through the streets. I've driven through the streets every day. You cannot go to any part of this city where it's not affected."
Gen. Keen was in Haiti on a pre-planned visit, staying at the ambassador's residence, when the earthquake struck Tuesday. "Three of my personnel were in the Hotel Montana that completely collapsed, so I can tell you it was devastating," he said. "It's like the Indiana Jones movie where the whole earth shakes. And we ran outside. His residence really was swaying back and forth. Fortunately it didn't collapse."
Two of the service members at the Montana were seriously injured and are being treated back in the States. "We are still searching for one," Keen said.
Complete Coverage: Devastation in Haiti
Keen said it will take a global effort to help Haiti. "We're going to need the entire world, the international community, to respond. We're seeing it happen every day, and we're very grateful for the support we're getting from our nation and all those around the world."
Dr. Rajiv Shah, the head of USAID, also described the Haiti quake as "an unprecedented situation and an unprecedented natural disaster."
Dr. Shah, who had traveled yesterday with Secretary of State Hillary Clinton to meet with Haitian officials and others involved in the relief effort, said that disaster response teams have been deployed, as well as five urban search-and-rescue teams of more than 70 people each. We have a few hundred professionals, well-equipped with dogs, out there saving people. Our teams alone have saved dozens of people, mostly Haitians. They've also coordinated an effort with 27 other countries, almost 30 other teams to help do that.
"Security is a key component of a humanitarian assistance operation where we need to create a safe and secure environment to ensure we're able to do everything we can. Our United Nations troops have been here on a mission of security and stability, continue with that mission, but they also have transitioned into humanitarian assistance, so the capacity to provide adequate security will be a challenge."
Dr. Shah said the problems facing relief workers are multi-faceted. "We're working on multiple issues simultaneously. One is securing commodity flow and getting that into Haiti. The military has been very successful at increasing it by more effective management of the airport. That's been a great first step. We now need to expand alternate routes including port-sea access. We're working in partnership with the Department of Defense to make that happen as quickly as possible.
"The second is we're trying to dramatically expand the in- country distribution network. We're working with our partners around the world, as the general mentioned, to identify as many major distribution points as we can, get those secured, improve transport to those points, and really dramatically accelerate commodity flow there."
Gen. Keen reported that yesterday paratroopers of the 82nd Airborne Division delivered more than 70,000 bottles of water and more than 130,000 rations - separate from what U.N. forces and other countries are doing. "But we need to do more. We need it faster."
Part of the challenge is the airport at Port-au-Prince, which currently has one working runway and taxiway.
When asked about the security situation, Keen said there have been isolated incidents of violence. "But I can tell you our paratroopers were out yesterday delivering humanitarian assistance, everywhere they went they were warmly welcomed by the Haitian people. They stood in line and were very warmly receiving our paratroopers and very grateful for that aid.