Ebola crisis calls for 'strong' action, Obama tells United Nations

(CNN) -- The West Africa Ebola outbreak is "a growing threat to regional and global security," U.S. President Barack Obama said Thursday, telling a high-level meeting on the deadly epidemic at the U.N. General Assembly that only an international response can prevent "a humanitarian catastrophe across the region."

"If ever there were a public health emergency deserving of an urgent, strong and coordinated international response, this is it," the President said.

Obama has declared the epidemic -- which is centered in Guinea, Liberia and Sierra Leone -- a national security priority amid fears it could spread farther afield and claim many more lives.

"This is more than a health crisis," he said. "This is a growing threat to regional and global security. In Liberia, Guinea and Sierra Leone, public health systems are near collapse. Economic growth is slowing dramatically. If this epidemic is not stopped, this disease could cause a humanitarian catastrophe across the region."

The President singled out Sierra Leone, where on Wednesday the government declared a success a three-day nationwide lockdown put in place to help stop the spread of Ebola, saying it had revealed more cases hidden in the community. Under the plan, no one was allowed to leave their homes for three days, from September 19 to 21, allowing volunteers to go door-to-door to educate people about the deadly virus.

"The courageous men and women fighting on the front lines of this disease have told us what they need: more beds, more supplies and more health workers, as fast as possible," Obama said. "Right now, patients are being left to die in the streets. ... One health worker in Sierra Leone compared fighting this outbreak to 'fighting a forest fire with spray bottles.' "

Obama called the outbreak an "urgent threat to the people of West Africa but also a potential threat to the world." A rapid global response to the crisis "could be the difference between tens of thousands of people dying and perhaps a million people dying," he said.

The President also highlighted United States' efforts to help, including establishing a military command in Liberia to support civilian efforts. But he urged international organizations and businesses to move faster to mobilize partners on the ground, and nations to contribute everything from air transport to health care workers to equipment.

"We are not moving fast enough; we are not doing enough," Obama said. "Right now, everybody has the best of intentions, but people are not putting in the kinds of resources that are necessary to put a stop to this epidemic."

The head of a medical organization at the forefront of fighting the Ebola crisis also appealed to world leaders at the meeting to take immediate action or risk losing the fight to contain the epidemic.

"Generous pledges of aid and unprecedented U.N. resolutions are very welcome. But they will mean little, unless they are translated into immediate action," Dr. Joanne Liu, international president of Médecins Sans Frontières, or Doctors Without Borders, said, according to an advance transcript of her speech.

"The reality on the ground today is this: The promised surge has not yet delivered.

"The sick are desperate, their families and caregivers are angry, and aid workers are exhausted. Maintaining quality of care is an extreme challenge."

Liu said fear and panic have set in as infection rates double every three weeks in the worst-affected nations, while growing numbers are dying of other diseases like malaria because health care systems have collapsed.

"Without you, we fall further behind the epidemic's deadly trajectory. Today, Ebola is winning," she said.